A search is underway for the hacker or hackers who caused city-wide panic in Dallas after 156 emergency sirens were all heard blaring over the weekend.
It began at 11:42 p.m. Friday as the sirens, which warn about approaching tornados, suddenly went off. However, there was no inclement weather or tornados headed to the area.
The sirens were shut off and then turned back on more than a dozen times throughout the night.
Social media lit up with comments and the city's 911 system was inundated with more than 4,400 calls.
"I'm freaking out!" one person could be heard saying in a video of the sirens.
At 1:20 a.m. Saturday, officials regained control by shutting down the entire system.
“It looks like a hack caused the sirens to go off. Hacker(s) believed to be from Dallas area," a city spokesperson tweeted.
It is not known whether the incident was a prank or a prelude to something more nefarious.
Former FBI special agent Jonathan Gilliam told Inside Edition: "It can go anywhere from the mundane of hackers messing around to actual bad guys testing out the response capabilities and how fast they are able to repair those types of things."
Others saw the apparent prank as a wake-up call.
"This is yet another serious example of the need for us to upgrade and better safeguard our city’s technology infrastructure," Dallas Mayor Mike Rawlings posted on his Facebook page Saturday afternoon. "It’s a costly proposition, which is why every dollar of taxpayer money must be spent with critical needs such as this in mind. Making the necessary improvements is imperative for the safety of our citizens."