It took 100 firefighters to stop the forward progress of a brushfire that scorched about 21 acres Sunday inside Irvine Regional Park, in an unincorporated area of Orange Park Acres.
The blaze ignited near 1 Irvine Park Road around 12:30 p.m., according to the Orange County Fire Authority.
It started out about 1.5 acres, but ballooned to an estimated 21 acres before forward progress was stopped shortly before 2 p.m., the OCFA said.
No injuries were reported and no structures were threatened. The park remained closed, and the agency added that all animals at the park were safe.
Firefighters remained at the scene to do mop-up work and knock down any hot spots that might flare up, the OCFA said.
The cause of the fire remained under investigation.