Firefighters extinguished a building fire in downtown Denver Tuesday that darkened the afternoon sky.
The fire broke out shortly after 2 p.m. at 303 E. 17th Ave., said Mark Watson, a Denver Fire Department spokesman.
Multiple fire trucks were at the scene on Grant Street, along with Denver police.
Firefighters used ladders to access a parking structure alongside the office building.
At least three people were being treated for smoke inhalation, including two victims who were taken to a local hospital, said Watson.
The fire started in a couple of mechanical rooms on the top of the parking structure, Watson said.