The blaze drew one of Denver’s largest recent fire responses, knocked out power across parts of the surrounding area, and prompted state emergency management officials to open an overnight shelter for displaced residents in the nearby city of Glendale.

DENVER — More than 100 firefighters battled a three-alarm blaze Friday evening at a three-story apartment complex under construction in southeast Denver, officials said. The fire was still burning more than two hours after it started, according to Denver Fire. No injuries had been reported.

Robert Murphy, division chief of operations for Denver Fire, called it one of the largest responses the city had mounted in recent memory.

“It’s major,” Murphy said. “I can’t tell you the last time in Denver we had a three-alarm fire this big.”

The Denver Police Department said in a post on X that a major thoroughfare adjacent to the building had been temporarily closed in both directions. Murphy said some residents of a nearby apartment building were advised to leave because of the heat radiating from the blaze.

The Colorado Division of Homeland Security and Emergency Management said the fire caused “significant power outages.” Officials opened a temporary overnight shelter at an event center in the nearby city of Glendale to assist displaced residents.

The cause of the fire had not been reported as of the initial dispatch.