A 911 call centers in several states including Texas report outages overnight and said city leaders want, don't know what's causing it. ABC S Randon Alley has more on the outages and a warning from us officials overnight, multiple police forces across four states reporting their 911 phone lines were down including the entire state of South Dakota, one county in Nebraska, a police department in Del Rio, Texas and two departments in Nevada including the Las Vegas Police Department. There is no centralized 911 system in the country. So it's going to be some time before we know exactly how many systems are affected. Even landlines were unable to dial 911 into Las Vegas. Police. They urged residents to dial 911 on a mobile device and we will be able to see your number and we'll call you back right away the cause of the outages not clear overnight. But just yesterday, an analysis from the Homeland Security Department warned that 911 call centers have become a likely target for cyber attacks as hackers could steal personal information and police records to carry out additional crimes such as extortion and identity theft immediately when you have this type of an outage all occurring at the same time. The first thing that law enforcement is going to start thinking about, is it some sort of an attack, either a cyber attack or could it be that some sort of fiber optic system was physically damaged in some areas, people were still able to text 911, many services that were down overnight have now been restored. But the cause of the outage still remains unclear. Rhianon Alle ABC News, New York.