An ongoing issue with cell phone carrier T-Mobile may be connected to the death of two people in the Dallas area after massive delays in the 911 dispatch system followed an influx of hung-up calls. The root of the problem remains a mystery.

Police 911 dispatchers are often a lifeline in an emergency and are required to return every call that's hung up. Unfortunately, a problem with T-Mobile that began in November resulted in massive amounts of hang-ups, or ghost calls, that dispatchers had to manually return. As a result, two people died last week after being unable to reach a Dallas police dispatcher.