Forest Lakes Elementary School fire

A portable unit catches fire at Forest Lakes Elementary. (Handout photo courtesy Harford County Md Fire & EMS / February 28, 2013)

A portable classroom at the rear of Forest Lakes Elementary School was badly damaged when a malfunctioning heating unit started a fire early Thursday morning, according to Harford County fire officials.

The blaze at the school, in the 100 block of Osborne Parkway in the Forest Hill area north of Bel Air, was brought under control about 2 a.m. by several dozen Bel Air and Fallston volunteer firefighters, the fire department reported.

Damages are estimated at $15,000. No changes to the school's schedule on Thursday were reported.