No one was injured in a fire Monday evening when the roof of a building collapsed in Logan Square on the Northwest Side.

Fire crews responded about 9:45 p.m. to the Bright Metals Finishing building at 3905 W. Armitage Ave., which was unoccupied, according a Chicago Fire Dept. spokesman.

The roof of the building caved in and the building collapsed, the spokesman said. The fire was extinguished 30 minutes later. No injuries were reported.

The city’s department of buildings was responding, and the cause of the fire was under investigation, the spokesman said.