Work crews shoveled mud Friday from the back yards of several homes after a brief cloudburst unleashed flows of debris down steep mountains left barren by the largest wildfire in Los Angeles County history.
The incident occurred in a small section of a swath of foothill suburbs that the U.S. Geological Survey has warned are at risk of massive flows in the aftermath of the 250-square-mile Station Fire.
Damage was mostly limited to landscaping and there were no reports of any injuries after the downpour late Thursday caused the San Gabriel Mountains to belch water, mud and rocks.
The USGS said in an emergency assessment of the area last month that two very likely scenarios _ storms lasting three or 12 hours _ could send debris far into the foothill communities. But USGS research geologist Susan Cannon had warned that it could happen even with a "wimpy little storm."
Gary Stibal, who has lived in the area since 1973, found his backyard buried under as much as 5 feet of mud that pressed up against his house. The top of a patio table was left flush with the new ground level.
Stibal said the downpour hit without warning about 10:45 p.m.
"It came down in buckets," he said. "I've never seen it rain that hard."
Mud began flowing within five minutes and Stibal and his wife drove away down the hill, Stibal said.
Clouds swathed the mountains at nightfall Thursday but the National Weather Service had predicted only about a 20 percent chance of light showers.
The NWS said Friday that the rain was "briefly torrential" in a few places. A few sites in the Station Fire burn area got more than a half-inch of rain but most areas had no measurable precipitation, the NWS said.
County Fire Department Inspector Frederic Stowers said 1 inch to 2 inches of rain fell in less than 20 minutes.
"It came very fast," said Lien Yang, as he shoveled mud from the driveway of his home in the same cul-de-sac where Stibal lives.
The Station Fire was ignited by arson on Aug. 26 along a highway through the Angeles National Forest.
Two firefighters were killed and 89 homes were destroyed. The fire was fully contained in mid-October but has not been declared controlled because root systems continue to smolder in the vast burn area.