Aurora firefighters were at a building with multiple residences, checking on smoke, when an explosion blew out an exterior wall of a fourth-floor unit.
Three people were injured in the blast, according to Aurora Fire Rescue, and were taken to hospitals.
Aurora Fire Rescue responded to reports of smoke at 14565 E. Alameda Ave., according to a 9:57 a.m. tweet. Firefighters were searching for hazards when the explosion tore out an exterior wall.
People were urged to stay away from the building, and units were evacuated, the fire department said. The building was damaged, and an investigation into the cause of the blast is ongoing.
Three hundred to 400 residents in the large five-story building are being displaced, according to fire department officials. The Red Cross is aiding residents, and RTD is helping with transport to a nearby shelter. Long-term accommodations and assistance will be provided by the Red Cross based on needs.