Widespread 911 outages in the US appear to have mostly been resolved, but that doesn't mean the cause is clear.

Reports began coming in last night that 911 services were down across the states of Nebraska and South Dakota, with parts of Texas and Nevada - including the city of Las Vegas - experiencing outages as well.

Del Rio, Texas, police chief Frank Ramirez told The Register that his department's outage was restricted to calls from just one carrier, T-Mobile, and that other service providers tested were able to get through without issue. As of this morning, Ramirez told us service has been restored.

But the opposite experience was the case in Nebraska, where the Chase County Sheriff's Office said 911 was down across the state "for all cellular carriers except T-Mobile." Landlines, the Sheriff's Office said, were unaffected.

Travel over to Las Vegas, and things were different there too. According to Las Vegas police, cellphone users were able to call the department, but not get through. "Dial 911 on a mobile device, and we will be able to see your number and will call you back right away," LVMPD said.

Unlike Nebraska's outage, 911 calls from landlines were reported to not be working in Las Vegas.

The Register contacted all of the law enforcement agencies that released statements on outages, but only heard back from Del Rio PD. Additional reports of 911 outages in other states could not be confirmed.

We also approached T-Mobile, Verizon, and AT&T to see if disruptions in their networks were behind the outages. Only Verizon responded, stating that its network was unaffected. That said, Verizon told us that some of its customers may have been affected if law enforcement centers were the source of the issue, but added that it hadn't received any reports from customers.

Ramirez told us his department hasn't been in contact with T-Mobile.

This wouldn't be the first time an issue at a cellular carrier had led to a 911 outage, with AT&T incorrectly updating a whitelist in 2017 leading to a five-hour outage across the US. Tech vendors have also been responsible for difficulties in reaching emergency services, with Google patching an issue with Pixel smartphones in 2022 that left some owners unable to call 911 when certain third-party apps were installed.

There's also been speculation that the outage may be related to a cyberattack, though there's no indication that's the case.

Nonetheless, the disruption was timed just after news broke of a Department of Homeland Security (DHS) assessment published earlier this month which found that 911 services were ripe targets for cyberbaddies.

According to ABC News' reading of the DHS report, emergency service providers have already been disrupted by ransomware attacks, and attackers are likely to find valuable information hosted on systems controlled by law enforcement and other agencies. ®

https://www.theregister.com//2024/04/18/911_outage/