Flash Flooding in California, October 7, 1997

Localized heavy rain developed over the San Bernardino Mountains in association with a fast-moving cold front and sharp, low pressure trough aloft. Between 1.5 and 2.0 inches of rain fell on a recently burned area southwest of Running Springs. Most of the rain fell in less than one hour, loosening debris and soil on Holcomb Hill, which flowed into, and blocked drainage through box culverts. The result was a six-foot wall of mud, debris and water flowing over cars, roads, and homes . In all, 27 homes , an apartment complex, Acquinas High School, and 14 automobiles were damaged. Also, trees up to two feet in diameter, along with boulders and other debris, blocked and damaged drainage channels and roads. The flood stranded four runaway teenagers, who had to be rescued by helicopter. They were treated for minor bruises and hypothermia. Total estimated losses exceeded $2.5 million.