More than 185,000 customers were left in the dark on Sunday as widespread power outages hit the Denver area, according to energy utility officials.

During the peak of Sunday’s outages, roughly 44,000 Core Electric Cooperative customers and 145,000 Xcel Energy customers were without power, according to the two utilities.

The widespread power outages also caused disruptions at Denver International Airport and law enforcement agencies across the southeast metro area.

As of 5:15 p.m. Sunday, all but a handful of Core Electric‘s power outages had been resolved, according to the utility’s outage map. Just 30 minutes earlier, reported outages included:

23,416 customers in Arapahoe County,
20,242 customers in Douglas County,
692 customers in Elbert County,
And 1 customer in Adams County.

The cause of the outages remained under investigation Sunday evening, Core Electric spokesperson Amber King said.

Xcel Energy spokesperson Michelle Aguayo confirmed in an email to The Denver Post that “a large outage” also impacted as many as 145,000 of that utility’s customers in the southeast metro area.

As of 4:45 p.m. Sunday, roughly 40,000 Xcel Energy customers remained without power, Aguayo said.

“It started at one of our substations and crews are on the scene working on repairs and finding the cause of the outage,” Aguayo said.

Sunday’s power issues reached as far as Denver International Airport, where trains connecting the airport’s concourses and other unspecified systems were disrupted, airport officials said. All airport operations had returned to normal Sunday evening, according to a 5:09 p.m. update from the airport.

Several local law enforcement agencies, including the Parker Police Department and Aurora Police Department, reported issues during the height of the afternoon power outages, including nonfunctional emergency phone lines and dark traffic lights.

This is a developing story and will be updated.

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