Minnesota's Fatal Structural Failure! - Massive Engineering Mistakes - Engineering Documentary

catastrophe strikes in the heart of Minnesota it lifted my car up I heard a loud boom and I thought that's it that's it a detonation disaster in Downtown Dallas are you serious what the heck is going on here in Denmark a rail tragedy on a Cutting Edge Crossing one of the most fatal and tragic uh accidents in in Danish train history it was horrific and in Iowa a devastating damn failure threatens an entire Community you don't have a minute you need to get out now with big builds even the smallest mistake can be a huge disaster from miscalculations to misunderstandings some with dead deadly consequences these catastrophes are every engineer's worst [Music] nightmare Bridge Engineers are in a constant fight with gravity every joint angle and dimension has to be perfect even a small miscalculation can cause a major [Music] disaster like this bridge failure in Minnesota a fatal collapse on one of the state's busiest Crossings seeing it crumbled in the river was nothing like I'd ever seen before this Rush Hour disaster revealed a deadly design flaw I thought I was going to die and you just waited for that wave of concrete to gobble you up and to take you away the tragedy left everyone asking why did it fail so catastrophically Minneapolis the name means waterfall City and it thrived thanks to America's most iconic River Stacy bangs is a local journalist Minneapolis was built around the Mississippi River there's so much life and color in the city it's a source of Recreation but more importantly the city is built around the power of the Mississippi River all that power carved a Gorge through the land and as the city grew so did the need to cross the river Minneapolis now has more than 20 Bridges crossing the Mississippi without them the city would grind to a halt the St Anthony Falls bridge is one of the busiest it carries I35 over the Mississippi a crucial connection on an interstate running from Minnesota to the Mexican border in 1964 construction started on the original eight Lane crossing the I35 Mississippi River Bridge engineer Dr Matt Rouse is a bridge research specialist so the I35 bridge in Minneapolis was designed and built in the 1960s the style of bridge this deetra the basic structure of the bridge has two of these large trusses which are parallel to each other and they support the deck that the traffic moves on each 325 M truss was a lattice of horizontal vertical and diagonal steel members all connected by multiple gusset plates this gusset plate is a steel plate that connects several of these trust members that all meet at a certain point so for example there's a gusset plate right here right which is Bolt or riveted to all of the individual trust members and that gusset plate holds those members together and if the stress gets too high on that gusta plate it can rip or tear gusta plates are found in all kinds of Steel structures not just Bridges but stadiums television masks even the Eiffel Tower they're like the glue that hold these huge objects together the 35W Bridge opened in 1967 and for four decades carried more than 100,000 Vehicles a day over the Mississippi the 35W bridge connects people that connects life it's part of the heartbeat of Minneapolis on August the 1st 2007 construction workers and cement tankers were on site waiting to resurface the bridge four of the eight lanes were closed Andy Ganon was Dr driving across town that day I was heading to a wake of a cooworker of mine whose father had passed away when I got on the bridge got on a little bit and first thing I heard was a loud boom and the bridge moved lateral and I thought well that was weird I thought maybe that was a barge that hit one of the beams in the water but this was no barge at 6:05 p.m. motion sensors triggered a surveillance camera The 40-Year-Old Bridge failed without warning so you watch the bridge buckle up and lifting cars up and some of the cars falling down over the sides it lifted my car up I remember being up above everybody heard a loud boom that was the bridge coming back down almost 140 M of the central span dropped into the river we all freeall and just rode it down and my life flashed before me and uh definitely thought that was that was going to be it more than a 100 cars went down with the bridge for about 3 to 5 Seconds was the most Eerie quiet the most Eerie silent and at that moment I actually thought I had died Deputy fire chief Don leam was on duty when the call came in 35 W bridg is right off to our left and normally it looks like that but on that particular day the cement kind of had a horizon line and you couldn't see the part that actually went over the river because it didn't exist anymore it was like nah that can't really be it as Dawn and the fire crew arrived the scale of the disaster hit home it became evident that they were they were going to be going into a very fluid situation the bridge had just collapsed it by no means seemed like it was stable at the time we still had cars up on top that were letting loose and sliding down and falling off the ledge journalist Stacy bangs also witnessed the devastation firsthand I only lived about three or four blocks away and I heard and felt something somebody even asked did you guys feel that and I looked out my balcony and I saw the fracture sticking up in the smoke I was in complete shock and my gut instinct was just to get my cameras and go there nearly 200 people had been on the bridge when it fell It Was a Race Against Time to rescue them it was shocking and it was unbelievable to see I was calling my wife to say goodbye I thought for sure I was going to die um if I could if I could if I could get her on the phone for even two seconds to say I love you um that would be good enough for me not everyone was as lucky as Andy 145 people were injured tragically 13 died the nation was left asking just what had gone wrong it's taunting to this day when I think about what people on the bridge went through when that went down I think we were all just kind of in a collective shot [Music] back in the wake of the disaster an investigation was launched to discover why the bridge had collapsed and why so suddenly one question was whether the combination of construction equipment and heavy rush hour traffic was to blame these added more than 600 tons of weight to the center span but that in itself shouldn't have triggered the collapse detailed inspection of the CCT TV delivered a crucial clue by analyzing the footage investigators were able to pinpoint exactly where the fail started and they discover it was a specific set of gusset plates the very things that held the bridge together the first part of the bridge to fail was identified on the south side of the central span with gusset plates known as the U 10 node the steel plates were found to have buckled and fractured completely as the bridge dropped the exact same plates on the North side cracked and the center span was doomed Bridge specialist Dr Matt Rouse explains this type of bridge is very nonredundant so if there is a localized failure which causes one of the trusts to fail the whole Bridge comes down so why did these critical plates fail investigators uncovered a tiny but crucial design floor in the original plans this gusset plate that we're talking about that filled is about 10 ft wide and 6 fet high it's a huge piece of Steel and it this one in particular that failed was about a/ inch thick and according to the code and the design standard it should have probably been closer to an inch in thickness it did not meet the standards of the day and it certainly didn't meet the standards of today that small all miscalculation ultimately proved catastrophic and yet the bridge had stood firm for 40 years with the flaw hiding in PL sight City historian Lori Williamson explains this is a Infamous gussa plate from the 35W bridge over the Missippi river that collapsed in 2007 I think it was a combination of design flaw from the get-go of it not being thick enough but I also think that there was a lot of wear and tear on it that weakened it to a point where It ultimately failed Decades of pounding by traffic and the weight of construction equipment proved to be a lethal [Music] cocktail it was a perfect storm of all the right combinations it couldn't take it and the whole Bridge came down the city was in mourning but the I35 was a vital link and had to be replaced on September 18th 2008 just over a year after the tragedy the new 10 Lane St Anthony Falls Bridge opened to traffic this time Engineers weren't taking any chances Bridge engineering had come a long way in 40 years instead of a fractured critical steel trust which risk collapse if one plate failed the new bridge uses multiple concrete GDs meaning it's a much more robust safer Crossing so for example example instead of two major structural elements of two parallel trusses we might have several parallel beams each which supports a smaller portion of the deck and the idea there is that with the more with more redundancy uh the consequences of a local failure are much smaller Minneapolis was on the move once more but lessons from the failure continued to reverberate through the engineering community this bridge collapsed Departments of trans Transportation all around the country suddenly scrambled to increase their inspection programs especially bridges of similar design to make sure that they didn't have um a similar situation on their hands that had gone undetected he was a reminder of the risks in older infrastructure in Minnesota inspectors now assess fracture critical Bridges at least every 2 years what I've taken from this situ situation is really a broader look on life and my own life and what really truly matters what really doesn't matter because when you come close to dying at that moment I remember going I don't want to die cuz I'm not [Music] done every engineer knows that careful planning is the key to success but sometimes even the best laid plan go disastrously [Music] wrong Like This calamity in Texas where a routine detonation turned to disaster when you're using well over 100 kilos of dynamite you really hope you've got things right an explosion that made headlines for all the wrong reasons are you serious what the heck is going on here and a building that just wouldn't go away safe to say this demolition didn't go to [Music] plan Dallas Texas is a big city with a Southern can do attitude journalist sha O'Neal explains the symbol of Dallas is a Pegasus it's an ordinary creature that becomes extraordinary it's a Workhorse that Sprouts wings and flies up above everybody else and that's Dallas in some ways Dallas might have a reputation for its oil and its Cowboys but there's a lot lot more to this city than meets the eye Dallas made its bones and oil but oil is just one of the many things it's just got its hand to just about everything it's always out there every day just selling itself one of Dallas's boldest marketing ideas grew out of the long baking hot summers in the 1920s in Dallas you had this place called the Southland ice company and they were just selling ice out of their storefront one of the employees this guy named John Jefferson Green he realized that you know he could sell milk and eggs and bread and that sort of stuff out of their storefront it was a convenience for people the idea quickly caught on and by 1946 was spread across Texas renamed 7eleven they decided after World War II to change their name to reflect the hours that they were open by the 1960s 711s were everywhere in the 1970s this fast growing company needed a brand new head quarters built around 3 km north of downtown in typical Dallas style it would be bold and strong at heart Thomas Taylor was the principal design engineer these are the original plans and they were completed in 1971 I had this idea as a young engineer to make something more out of it than just a standard routine building so we came up with the concept to actually use the facade that the expression of the building actually use that as structural standing around 48 M tall the outside of the 11-story tower would be built from pre-cast concrete panels and steel but its real strength would come from within supported by a solid cast in place concrete core that would both stabilize and provide structural rigidity the whole purpose of the concrete core was to tie all the pre-cast and steel floors with steel beams to the concrete core so they won't fall over If This Were a tree that would be the tree truck these days pre-cast panels can be made strong enough to play a structural role but back in 1971 they were mainly cosmetic so this building's solid concrete core was essential the primary purpose is to keep it from blowing over there's a 11-story building with a plus a basement so the wind pressures are pretty high so obviously a core is extremely important because it's the whole lateral stability of the building by the 80s 7-Eleven had moved on and in 2020 the tower was scheduled for demolition to make way for $25 billion Redevelopment built in the 70s so you know that's 50 years ago so that it had a good long life Sunday February the 16th 2020 demolition day there's two ways to demolish a building one is just knocking it down with heavy balls or something but then the other is to implode it more than 100 kg of dynamite were primed and ready to [Music] go [Music] when that first implosion hit it took down everything else it took down the steel bars the windows all the kind of frippery if you will and it just left this solid concrete Core built to withstand hurricane force winds the core had just stood up to more than 100 kilos of explosives shaken but still standing the core only dropped around 10 m and was left with a t of 15° that's more than the Leaning Tower of Pisa local street artist Gerald CER knew that this was too good an opportunity to miss my brother called me and he said uh hey did you hear about the Leaning Tower I what you yeah I know the Leaning Tower everybody go no no the one in Dallas I what so I came out here and the spectacle was something that I I just had to to capture I hadn't seen anything like that as Gerald memorialized the catastrophe on canvas the core quickly became known as the leaning tower of Dallas it became a real tourist attraction people started going to it specifically to take photos like you would in Italy with the Leaning Tower Pizza you know pretending to hold it up or kick it over or whatever the dallasites kind of were fond of it you know this is our LAN power it was a fun time one of them started a petition asking for it to be made a UNESCO world heritage site there were calls to make it a permanent tourist attraction obviously there's a lot of safety concerns with that sort of thing but how had a supposedly routine demolition gone so spectacularly wrong engineers build structures to last not fall over so when you're planning to use explosives to bring one down it's crucial to know exactly what you're blowing up that's kind of how we built it back then we didn't build them to make them easy to demolish it seems the core might have been stronger and more stable than expected this wasn't news to the the tower's principal engineer I wasn't surprised that the core was hard to come down if they didn't have a proper number of charges or if the timing was bad or maybe a charge didn't go off at the exact time it supposed to go off maybe they under the size their charges I don't know one explanation was that the dynamite would blast the pre-cast concrete and steel floors while cutting the core off at its base toppling It To The Ground like that tree but one thing they might not have bargained on was the basement if you look at it closely it looks like it fell in the basement so it actually did fall down and I think maybe the rubble of all of this other stuff that was in there was surrounding the core and so when it tried to fall over laterally the rubble around it is probably what contained it and prevented it from being able to fall over the core was wedged in and leaning at around 15° so on February 24th 8 days after the blast it was time for Plan B the wrecking ball if they needed 135 kilos of dynamite to blow it up you'd think they would need a giant wrecking ball too but think again to take down the 11 story concrete core was a 2,500 kg wrecking ball just over 1 M High there was was a silence in the crowd and then there was the a great exhale of what the heck is going on here are you serious is that what they brought what dallasites were witnessing wasn't blowing them away but I don't know how big a wrecking ball you can actually get but you know especially from a distance it just looks like this little like Cannonball just taking pot shots at this building literally it looks like my paintbrush coming up to the side of the building here and [Music] then the ball would just bounce off of it and just bounce off of it eventually the local news set up like a live stream you could watch a 24 hours a [Music] day all day [Music] long that Wrecking Ball might have looked underwhelming but at least I got the job done eventually on the afternoon of March the 2nd 15 days after the blast the leaning tower of Dallas finally leaned no more it was over it was done everybody stood around everybody that was there all that was left was just a pile of Rock with the land now leveled and despite the Calamity the lean Tower left a lasting impression on the city it brought the community together and allowed us to focus on something that was outside of ourselves and one thing is for certain the core was definitely up to the job it does kind of prove that it was strong enough to resist the wind cuz I know was what it was intended to do everybody in Dallas knows and loves the lenan Tower of Dallas the tower is gone but it's not [Music] forgotten Engineers are on a constant quest for Simple Solutions to complicated problems but it only takes one oversight to turn a fix into failure like this Railroad disaster in Denmark on one of Europe's most iconic Bridges this was a ticking Time Bomb no one had any idea there was a problem until it was too late a hidden design floor with tragic consequences one of the most fatal and tragic uh accidents in in D train history a deadly discovery that sent shock waves across Europe we warn the other investigation bort in Euro this could be safe to critical [Music] Denmark for centuries the capital Copenhagen on the nation's biggest island could only be reached by boat Stefan Jorgenson is a local journalist Denmark is a small country separated by many islands if you had to travel from the western part of Denmark to the capital of Copenhagen you had to take Ferris it took hours but then in 1998 the great belt Bridge was constructed and everything [Music] changed with a main span of just over 1 and a half km the great belt fixed link is the third longest suspension bridge in the world Standing Tall this Mammoth Crossing revolutionized Denmark's Transportation Network the great Bel Bridge which totally redefined the infrastructure of this country so what took an hour before Crossing by ferry uh now takes not more than 10 minutes this crucial link helps connect Northern Scandinavia with the rest of Europe to the South by both Road and Rail and sometimes a clever combination of both known as piggybacking for about 40 years Europe is used rail network to carry Road Freight semi-trailers piggybacking on specialist rail cars called pocket wagons instead of being towed by a truck the trailer sits in the wagon like being in a pocket the only fixed connection is where the trailer's Kingpin slots into the rail car's saddle with teeth that grip it in place all secured by a locking arm this tried and tested method was transporting Freight safely across the Great belt Bridge and into Europe for decades January the 2nd 2019 a 110 km hour storm was battering the coast of Denmark the great belt Bridge was right in its Firing Line and closed to road traffic but open to rail local journalist Stefan Jorgenson was on the train to work I was crossing the great bu bridge and um approximately about uh half past 7 uh the train stopped in the middle of the bridge and in in the speakers they announced that we had to stop because a cargo train had to drop something some kind of tarp on the tracks and that we couldn't proceed Chief accident investigator Bo hanning was on duty at the time we got a phone call from the D State Railways there b who told us that has been some incident on the great belt maybe some passengers had got wounded a bit it was far worse at 7:29 a.m. a commuter train heading to Copenhagen collided with a semi-trailer hanging from a freight train we pretty quickly found out that it wasn't just a tarp on the tracks it was a lot bigger than that it was very serious moments before the incident CCTV captured this grainy footage the the empty trailer had fallen Sideways from the freight train and was being dragged into the path of the oncoming commuter train both were traveling at around 120 km an hour by the time the passenger train saw the trailer it was too late in a very few second there was huge damages along both the presenter train and the flight train 131 passengers were on board when the front Carriage hit the trailer 18 people were injured sadly eight lost their lives what started out for me and I guess many other journalist as a quite normal day quickly turned out to be an extraordinary day with one of the most fatal and tragic accidents in in D train history this accident was on one of Denmark's busiest Bridges between two regular rail services so B knew they had to uncover the cause of the disaster it was important for us to find out as fast as possible what happened not not only what happened but why for me I can describe this as a big puzzle and we have to find all the parts to put together the accident spread wreckage along hundreds of meters of track the Collision actually was just after the where the bridge started and then the passenger train uh broke and and stopped a few hundred meters uh after and the flight train continued here on the line and actually stopped around here with the locomotive just over there and and with the with the wagons up here the semi-trailer had been dragged sideways by the pocket wagon until it was knocked completely clear by the passenger train Bo and his team faced a massive challenge finding evidence it was a train with empty beer bottles in boxes so there was glass bottles all over so we was trying to locate which part on the on the track was actually a part of the accident and was trained part from the flight train or from the passenger train the big question question for B and his team was why the semi-trailer had fallen from the pocket wagon so investigators focused on the only connection between trailer and rail car the Kingpin and saddle we had three main scenarios one of them was that the semit triler was correct loaded but not locked one of them was actually that it was wrong loaded and the last scenario was that it was correct loaded but the wind was strong enough to draw it down just 6 days after the crash with the investigation still underway the Danish authorities banned all pocket wagons from the rail network suddenly uh goods from going from Germany for example to Sweden couldn't cross in Denmark with these kind of wagons these kind of pocket wagons were banned until the companies could reassure the Danish authorities that it was safe to find out how the 7 ton semi-trailer had been blown from the pocket wagon the team brought in professors Yen senson and Robert Mickelson wind experts from the Technical University of Denmark we used a model train which is identical to the real train uh and put that into a wind tunnel to measure and test visualize and investigate how the the wind was blown around the bridge and the Train by simulating the exact conditions on the bridge that morning Yen and Robert discovered that strong winds combined with the speed of the train were enough to blow the empty trailer off the pocket Wagon on one condition we found out that a wind speed in the order of 22 m/ second was sufficient to crash this down here provided that the king Rod was not attached the theory was tested at full scale with an empty TR trailer in equivalent winds proving that if unlocked the Kingpin could be blown from the saddle but according to reports the Kingpin had been properly locked in place if it was locked correct and you lift in the Sim trailer it is so heavy the lock that you could lift the wagon the whole wagon and you don't have wind powers enough to derail both a wagon and a semit trailer in a train on closer investigation they discovered a previously unknown floor in the pocket wagon system the Locking teeth on the saddle weren't always locking the problem was really very simple although the operating lever looked to be locked the teeth in the saddle weren't always fully closing around the Kingpin meaning it wasn't locked at all and this floor was made worse by maintenance access issues we could see that actually the maintenance of these locks was not done for several years to be sure that the lock could work you have to open and to duplicate the Bene of the lock to be sure all the parts inside could work and it hasn't been done while it's clear proper lubrication was safety critical it wasn't mentioned in the guidelines this is one of those problems that goes unnoticed until a disaster brings it into the light pocket wagons had been hurtling around Europe unsecured for years the combination of the trailer being empty and exposed to high winds on the bridge revealed the problem very dramatically with the cause of the accident identified new maintenance guidelines for locking mechanisms were implemented throughout Europe this was one of the consequences to be sure that other hitches of this type wouldn't have uh risk the same failure in the future in the wake of this accident the rules were changed requiring these crucial connections to be serviced regularly so hopefully nothing like this can ever happen again Engineers say mother nature always bats last and when it comes to big construction her strike rate can be devastating like this damn collapse in Iowa on a collision course with an entire town we could be wiped out it was scary this is my town what's going to happen if it's wiped away hundred hundreds evacuated in a catastrophe of Epic Proportions you don't have a minute you need to get out now an engineering mistake exposed by Mother Nature the power of water was single rainfall event almost without warning can result in the failure of a dam that's been in existence for roughly 100 [Music] years Iowa in the heart of America is home to hundreds of rural communities like Hopkinton a small town that grew up on the banks of the makoka river Kathy Harris is former mayor Hopkin has always been my home it has grown I mean we're a population of 628 now I enjoy the Small Time Life when somebody's sick somebody needs something we're there for them and and that's just the way hot kitten is so that's why it's so special to me around 15 km up River lies Lake delh high now a hot spot for fishing and Recreation its dam was once a source of power for Hopkinson delh High dam was built in the 1920s as a hydro electric power station and generated electricity for about 40 years until the turbines were Switched Off in 1973 engineer Randy rattenberg is president of the Dam's operating company these are the original inlets where the turbin were this is where the water would flow into to spin the turbin right now we're in the turbine room these are original from the construction of the dam so the purpose of these turbines was to generate the hydroelectric power which was reason the dam was built to begin with completed in 1929 the dam beside the PowerHouse had a 26 M wide Spillway designed to release water during periods of high flow the old Dam had three gates we're actually standing over the top of them right now this area is part of the original structure built in the 20s holding back the rest of Lake delhigh was a 100 150 M long earn embankment around 18 M high with a reinforced concrete wall at its core to Anchor the dam in place professor of engineering Larry Weber is a Hydraulics expert in many cases there will be a portion of the dam that's concrete uh that's where the structure of the dam is and then there's a larger Earth and embankment just to hold the water back for more than 100 years the dam controlled the flow of water to the river below While Lake delhigh itself became one of the County's most sort after suburbs on July 22nd 2010 a heavy storm began to fall on the makoka river at one point 25 cm fell in just 12 hours and so there was a warning that went to communities Downstream of a potential Dam failure at Lake del high if the dam burst the small town of Hopkinson would be the first in its path in the early hours of the morning mayor Kathy Harris received a knock at her door it was about 6:00 on July 24th I looked out my bedroom window and I see the fire chief I said what's going on Craig and he said they think the dam is going to break we are evacuating this area Del High Dam engineer Randy rattenberg had a bird's eyee view of the impending disaster me and another guy we're up in a plane and we were taking pictures I'm watching and I'm just like wow this is really bad this is not going to go away anytime soon Randy was right at 12:49 the roadway across the dam dropped into the Deluge 11 minutes later the entire embankment failed all the water that was being held back from Upstream went downstream it was pretty dramatic around 2 million lers of water per second were now flooding down river rocks and Roads straight towards hopkington there's houses that are just gone now because the ground that they were sitting on doesn't exist anymore it's gone as the torrent continued the outskirts of Hopkinson were engulfed in a wall of water when it came it came with such a force when you looked at it it looked like a big ocean down here it came over the the road here and back through here that is the highest I have ever seen the water it was scary when the flood subsided questions were being asked why had this historic Dam failed was it an act of God or an engineering catastrophe sound could have been gone it's just it was scary something that I'd never want to live through again in the aftermath of the disaster an investigation was launched to find out exactly what had gone wrong the Dam's three Spillway Gates designed to prevent an overflow with the first Port of Call a year before the dam burst it was clear that one of the spillway Gates needed repair but by the time the dam broke the works didn't appear to have been completed they had two of the three gates opening the third one was opened partially but it was not able to be opened completely the investigation concluded that even a fully functioning third gate wouldn't have saved the dam at its peak more than 2 million lers of water were pushing against the dam and every second even with all three gates fully open the spillways could only cope with half that amount and so that caused the lake level to rise more and a little faster until ultimately the lake level Rose to a point where it over topped the dam evidence in the rubble explained why the over topping had caused such destruction in the embankment the height of the concrete core the concrete core in the dam was at a certain design height the lake level Rose to a point higher than that that caused seepage to happen and that water seepage caused some erosion to the interior core of the dam the reinforced concrete wall was around 1.8 m lower than the top of the embankment as flooding made its way over the top water eroded the Earth in a process known as piping and the whole thing started to collapse piping happens when fast flowing water gets into a dam or embankment eroding soil and creating a long cavity or pipe in some cases it can cause a catastrophic failure of the structure as it overtopped the force of the water was simply too much for the 80-year-old structure to bear this event tested that Dam to a level it had never seen before a single storm in the makoka river it was a single Watershed but in that water shed it was devastating in the wake of the collapse the dam was redesigned reinforced and reopened in 2016 this time with an award-winning Spillway the first of its kind in Iowa the aptly named [Music] [Music] Labyrinth the Labyrinth is kind of a zigzag shape and this Labyrinth controls the pool and it also allows for the river just to maintain its normal flow as if this dam was never here the shape effectively makes the spillway about three times longer than a straight design in the same space meaning the Labyrinth can pass huge amounts of water compared to the old Spillway it's a night and day comparison there is no comparison with this design it's going to make make it safer for the downstream people as far as not having a major catastrophic flooding event happen again The Rebirth of the dam and the lake has reinvigorated the community and the local economy and for this area at least will hopefully make the catastrophe of 2010 a very distant memory Hopkin could have been wiped off the map and it wasn't so we were very very lucky we just pray and hope that it never happens [Music] again

Channel: Banijay Science

Views: 82,491

Keywords: Catastrophe Analysis, Infrastructure Failure, Minnesota Bridge Collapse, Tragic Accidents, buildings, construction fails, documentary, engineering, engineering challenges, engineering disasters, engineering documentary, engineering errors, engineering fails, engineering lessons learned, engineering mistakes, failed constructions, fails, massive engineering failures, mechanical engineering, saving buildings

Id: 13i4qDCv_Z4

Length: 45min 11sec (2711 seconds)

Published: Fri May 10 2024