A rude awakening overnight Thursday for likely thousands of Fort Worth residents, as the emergency siren system in the city rang out at approximately 1:30 a.m.
The cause of the sirens was a malfunction, according to Juan Ortiz, the Emergency Management Coordinator for Fort Worth.
Fort Worth Emergency management tells NBC 5 they still haven't been able to determine what caused the city's 150 sirens to go off.
"This is the first time that the system has had this type of malfunction," Ortiz told NBC 5.
Emergency management said Thursday afternoon the control device that operates the sirens, similar to an airplane's black box, will be sent off for testing. That process is expected to take several days.
The sirens were triggered shortly after 1:30 a.m., and sounded for upwards of two minutes, according to multiple sources.
Calls about the sirens flooded the NBC 5 newsroom from locations near the campus of Texas Christian University, Benbrook and Burleson.
The Fort Worth office of the National Weather Service tweeted about the sirens shortly after the incident.
"The Outdoor Warning Siren at our office went off at 135am. Be advised, there is NO hazardous weather/events in the area! #txwx"
Most troubling for those investigating the cause, aside from identifying the reason for the malfunction, is concern that residents might not heed the warnings in the future.
"Anytime that the system malfunctions it jeopardizes the integrity of the goal, which is to alert and warn citizens of an emergency or impending disaster," Ortiz said.
In order to determine the cause of the malfunction, the system's automatic function has been disabled, meaning they would not automatically be triggered if an actual emergency were to arise.
Ortiz said while the system won't trigger automatically, there will be a person at the controls who can manually set off the sirens in the event of true danger.
Sending the control device away for testing would not impact siren operations according to Fort Worth Emergency Management officials.