Several states experienced 911 call outages Wednesday evening, which emergency call system service provider Lumen said were caused by a light pole installation done by a third party.
A Lumen spokesperson said Thursday in a statement to ABC News, "Some customers in Nevada, South Dakota, and Nebraska experienced an outage due to a third-party company installing a light pole -- unrelated to our services."
"We restored all services in approximately two and a half hours," Lumen said. "Our techs identified the issue and worked hard to fix it as quickly as possible. We apologize for the inconvenience and appreciate our customers' patience and understanding."
The Federal Communications Commission is investigating.
The outages impacted areas in Nevada and Nebraska, as well as the entire state of South Dakota.
In Nevada, the Las Vegas Metropolitan Police Department said service had been restored in the city just before 9:15 p.m. PT Wednesday.
"All of the individuals who called during the outage have been called back and provided assistance," Las Vegas police said.
Nevada State Police also confirmed that service had been restored for southern Nevada's Clark County, which includes Las Vegas and Henderson.
The entire statewide emergency calling system in South Dakota experienced an outage, according to police.
The South Dakota Department of Public Safety said the interruption lasted from about 8 p.m. to 11 p.m.
During the outage, "The State 9-1-1 Coordinator was in constant and extensive communication with the state's 9-1-1 service vendor, Lumen, and the state's 28 9-1-1 dispatch centers," the department said.
"Although some calls may not have gone through, the system allows dispatch centers to identify the phone number of callers and return those calls. The 9-1-1 system is fully operational and ready to respond promptly to any emergent situation," the department said.
"Last night's outage was unprecedented in terms of its duration and magnitude," Sioux Falls Division Fire Chief Mike Gramlick said at a news conference Thursday. "Our team at Metro Communications, which serves as the public safety answering point for the area, handled the situation with exceptional professionalism."
Dundy County, Nebraska, and surrounding areas experienced outages, but both cellular and landline 911 service were later restored, according to authorities.
Multiple cities in Texas also reported outages, but those appeared to be unconnected, as Lumen said it does not provide 911 service in Texas.
ABC News' Darren Reynolds and Victoria Arancio contributed to this report.