Residents in four North Texas cities, including Rowlett, Garland, Wylie and Plano, experienced 911 issues Monday morning.
The 911 problems were resolved in all four cities by the afternoon.
The problem in Rowlett started at about 10 p.m. Sunday, when call takers were unable to hear certain callers or see their callback number, said Rowlett Police Lt. David Nabors. The issue was only with those calling in from cellphones, regardless of the provider. Land lines weren't affected.
Rowlett contacted Garland and began to transferring their emergency calls to Garland's 911 center, a standard practice when Rowlett's 911 center is down, said Nabors.
Garland was already experiencing similar issues, which began around 4 p.m. Sunday, said Garland Police Lt. Pedro Barineau. However, call takers the were able to see contact information and immediately make call backs, said Barineau.
Since the issue began at about 4 p.m. Sunday through 8 a.m. Monday, Garland's 911 call center received 371 calls. Of those, 283 were from cellphones. Dispatchers were able to call all of them back.
Lt. Nabors said the issue was with a Frontier transmission line between Lewisville and Denton.
In Plano, T-Mobile users who called 911 weren't heard due to a separate issue. T-Mobile said it was forwarding 911 calls to the direct 911 line. It wasn't clear what caused the issue in Plano, but a city of Plano spokesman said T-Mobile also uses Frontier lines.