Los Angeles County fire officials said the brush fire began as a trailer fire that then spread to about 2 acres.
It was reported in the 4700 block of Crown Valley Road, where large plumes of smoke were seen over a large portion of land.
At one point, a fire department helicopter appeared to stop an oncoming train headed toward the brush fire.
The fire appeared to be contained by about 12:45 p.m. Fire officials confirmed the fire was declared a knockdown shortly before 1 p.m.
The nearby train tracks were expected to be closed for over an hour as crews cleaned up the scene.