T-Mobile Executive Vice President David Carey echoed this sentiment during the press conference.

“We provide the same service all across the country,” Carey said. “There is something unique in this complex or system here, which we have not been able to identify. What we’ve done across the nation has been the exactly same thing that we’ve done in Dallas.

“Can we adjust some variables on our side to improve the situation? Yes, we’ve done that, and we’ll do a couple of more things that we created today. Is there something else unique in the environment here that’s causing this condition? The answer is clearly ‘yes,’ because we’re not seeing it somewhere else, but we don’t know exactly what that is.”

On Thursday, officials for the city of Dallas and T-Mobile reached a consensus on the matter, issuing the statement that the PSAP’s problems stemmed from abandoned calls—hang ups—instead of “ghost” calls.

One key issue contributing to the large backlog of 911 calls in Dallas is the fact that policies dictate that a cell phone being used to make a 911 call cannot receive any other calls—even call-back attempts from a 911 center after a previous emergency call is abandoned, according to Sana Syed, a spokeswoman for the city of Dallas.

“What’s happening is that these call-takers see a hang up, and they don’t know that this person is also on a live call right now, holding [for 911],” Syed said during an interview with IWCE’s Urgent Communications. “But they’re trying to [call back] the hang up to make sure that it’s not an emergency, and they can’t get through—because that person’s holding, and you cannot get through when a person is on hold with 911, because it’s considered an emergency call.

“So, the snowball effect of that is what led to these spikes in calls.”

With this in mind, officials for the city of Dallas and T-Mobile emphasized that emergency callers should remain on hold to get the quickest response, instead of hanging up and calling 911 again.

In an effort to address the 911 delays, the Dallas PSAP will utilize 12 additional call-takers per day—about a 25% increase in personnel answering emergency calls, Syed said. T-Mobile has agreed to optimize its network in a manner that will provide a longer “window” of time for call-takers to answer emergency calls. In addition, the Dallas PSAP is considering the implementation of technological upgrades, such a queue that allows call-takers to distinguish between hang-up calls and those that are “live,” she said.

“It’s a combination of factors—it’s that, it’s us not having enough people in the 911 call center, it’s outdated infrastructure—that have led to this issue,” Syed said. “T-Mobile has said they’ve addressed some things through their network, we’ve increased capacity, and we’re looking at the technological upgrades.

“For the next two weeks, we’ve got folks monitoring this around the clock. We’ve got folks in that 911 call center, so that—in real time—if something happens, they can see it happening, and they can put a stop to it. We’re hoping that we’ve figure this out. But really, it has to be tested now.”