SAN DIEGO -  

It took ground and airborne crews about a half-hour Friday to subdue a brush fire that blackened several open acres on a hillside northeast of Cuyamaca College.

The blaze began spreading near Jamacha Road and Brabham Street in Rancho San Diego about 3:15 p.m., according to Heartland Fire & Rescue.

Several emergency-services helicopters dropped water on the flames while grounds crews worked to get lines of control around the roughly 3-acre burn area, a dispatcher said.

No structural damage or injuries were reported. The cause of the fire was under investigation.