As flames continued to burn Tuesday inside a charred southeast Denver apartment complex, federal fire investigators were deployed to the city to help Denver firefighting crews determine the cause of the massive blaze.
Officials also said human remains search dogs had not found evidence of any bodies in the burned buildings.
The five-alarm fire, one of the worst Denver’s seen in decades, sparked Friday evening and tore through the still-under-construction luxury apartment complex at 5337 Leetsdale Drive in Denver’s Washington Virginia Vale neighborhood. The 283-unit complex, named Harker Heights, was valued at $23.2 million in 2025 and was owned by Texas-based real estate investment company Embrey.
The cause of the fire remained under investigation on Tuesday, Denver Fire Department Division Chief Robert Murphy said during an afternoon news conference.
Federal officials with the Bureau of Alcohol, Tobacco, Firearms and Explosives deployed the agency’s national response team to Denver on Tuesday to assist with the investigation, according to a news release from the agency.
“This fire threatened the safety of our community and injured a firefighter,” ATF Special Agent in Charge Chris Ashbridge said in a statement. “The (national response team) is bringing federal resources and expertise to this complex investigation. It is a top priority for us because we understand the immense challenges this fire has created for residents and businesses.”
The response team — which investigates major fires, explosions and bombings across the country — consists of federal agents, fire investigators, explosives specialists, fire protection engineers, electrical engineers, forensic chemists, intelligence research specialists, digital forensic specialists, a medic and an explosive detection dog, according to ATF.
As of 1:30 p.m. Tuesday, several lanes of Leetsdale Drive near the fire remained closed. The right northbound lane and two right southbound lanes were closed between South Holly Street and South Forest Street, according to the Colorado Department of Transportation.
Investigators were looking into reports that a homeless person was in the building when the fire began, but that information had not been confirmed Tuesday. Fire investigators were also considering fireworks as a possible cause, Murphy said.
Flames were still burning inside the building on Tuesday, preventing firefighters from accessing the complex to search for victims who may have been hurt or killed in the blaze or to investigate the cause. While waiting for the fire to be fully extinguished, investigators have relied on witness accounts and surveillance video from neighboring businesses.
“Some of this fire we just can’t get to,” Murphy said. “It’s covered up, it’s hidden by collapse. I can’t send firefighters in there because of the danger of more collapse.”
Human remains search dogs were able to roam through part of the collapsed building this week, and, as of Tuesday afternoon, the dogs had not found any bodies, he said.
“Our entire team would like to express our deep gratitude to the emergency response teams from around the city who worked to contain the fire within the construction site and who continue to work to secure the site,” Embrey spokesperson Jeff Cowart said in a statement. “Our priority remains working collaboratively with Denver Fire, investigators and the community as the investigation continues to determine the cause and next steps.”
Murphy said the “enormity” of the building and the massive amounts of debris will make the investigation difficult and lengthy.
This is a developing story and will be updated.
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