Police say ‘glitch’ led to bomb warnings being sent to thousands.

Austin police admit to alerts mistakenly sent to residents outside of neighborhood.

Austin police on Monday acknowledged that tens of thousands of residents who were sent emergency alerts through their phones to stay inside in the wake of a fourth bombing attack in 17 days should never have received the warnings.

That’s because most of those residents were nowhere near the Southwest Austin neighborhood where another bomb went off Sunday evening.

Police used a FEMA warning system to notify the residents of Travis Country, a neighborhood with more than 1,300 homes near Southwest Parkway and MoPac Boulevard (Loop 1).

Instead, the alert ended up being sent to “the majority of the city,” interim police Chief Brian Manley said, leaving many people scratching their heads and wondering whether they should leave their homes at all in the wake of the latest attack. On Monday morning, Manley acknowledged that the alerts were a “glitch.”

However, no immediate cause for the error was available, according to officials.

The first alert came at about 11 p.m. Sunday — more than two hours after the bombing occurred — telling people to stay in their homes while police worked the scene. Then ringers went off again about 6:15 a.m. Monday, alerting people to stay indoors until 10 a.m. or call 911 if they needed immediate assistance.

The city used a warning system called the Integrated Public Alert and Warning System, which is managed by FEMA, to send out the bomb alerts Sunday and Monday. That system picks cell towers in the area authorities want to warn. Angel Flores, a spokesman for the city’s Office of Homeland Security and Emergency Management, said because of this, people outside of the targeted warning area can receive the alerts.

It was the first time the city had ever used FEMA’s system to make a warning, Flores said. In the past, the city has used a reverse 911 system in floods to notify residents.

When authorities request an alert, it is sent to the FEMA system. Officials there authenticate the warning, which local authorities can scale to a smaller area, such as an individual neighborhood, or their entire jurisdiction, according to FEMA. Then the FEMA system sends the alert to phone carriers, who determine how it will be dispersed. It was unclear on Monday where along that chain an error occurred causing the alert to be sent to more residents.