A fire early Tuesday at a large apartment building in Burnsville displaced residents of several dozen units and left two firefighters with minor injuries from a collapsed ceiling.

Police and firefighters responded at 6:47 a.m. to the Observatory Apartments, 15111 Greenhaven Drive, after a 911 call. When they arrived, fire was visible on a vertical row of three balconies.

Authorities evacuated residents of about 45 units -- about half the apartments. The American Red Cross reported that 55 units were evacuated and that 49 of those were at least temporarily uninhabitable.

Fire departments from Savage and Lakeville assisted in battling the blaze. At one point, a ceiling collapsed on a firefighter from Savage and a firefighter from Lakeville, injuring them slightly. They were treated at the scene. The Burnsville Fire Marshal was investigating the fire's cause.

The nearby Liv Inn Suites offered a room to each displaced family. The Red Cross and Salvation Army also assisted residents.