The old East Brainerd Elementary School on East Brainerd Road was the scene of what Chattanooga authorities described as a "small fire" around 3:30 a.m. Monday.
The first firefighter on the scene reported nothing showing from the front of the building but after checking around back, a Chattanooga police officer found a small fire near the rear of the building, according to a news release issued early Monday.
Firefighters broke through a classroom window to get their hose lines inside where they quickly extinguished the blaze, officials said. No injuries were reported.
Battalion Chief David Thompson said firefighters pulled a mattress out of the classroom, which suggests someone may have been using the classroom for shelter, according to the statement. An estimate on the damages was not available. The cause of the fire is under investigation.