Chapel Hill, N.C. — A fire early Friday morning damaged two units in an apartment complex off Church Street occupied mostly by University of North Carolina at Chapel Hill students.

Firefighters found light smoke and fire in an area between upstairs and downstairs apartments in the Chancellor's Square Apartments, 211 Church St., shortly after 2 a.m. Five Chapel Hill fire departments and an aerial truck from Carrboro Fire Department worked to put out the blaze. No one was injured.

Investigators determined that a ventilation fan in the bathroom of a downstairs apartment started the fire. No one was home at the time.

A neighbor who heard smoke alarms going off on in an adjacent apartment called 911.

"Without this early notification from smoke alarms, the fire likely would have grown much larger before detection," Deputy Chief Matt Lawrence, a fire marshal, said in a release.

Three apartments sustained fire and smoke estimated at $30,000.

UNC is on its spring break.