Storm Closes Roads, Schools and Restaurant : Weather: Heavy snow and a mudslide leave a few hundred motorists stranded overnight in Castaic. Power to 3,500 customers is knocked out.

The storm that pummeled Southern California on Monday night created a host of problems in the San Fernando, Santa Clarita and Antelope valleys, including partial or complete closure of freeways, cancellation of classes in the high desert and some alarming moments at an Agoura Hills restaurant.

High winds gusting up to 45 m.p.h. downed power lines and lightning knocked out transformers in the San Fernando Valley, causing power failures affecting about 3,500 customers in Encino, West Hills, Woodland Hills and North Hollywood, Department of Water and Power officials said. The blackouts began about 8 p.m. Monday and lasted for periods ranging from several minutes to hours, officials said. Some customers were without power until 2 p.m. Tuesday.

The rain also caused several large potholes on a 600-foot stretch of the eastbound Ventura Freeway, forcing closure of the left lane between Haskell and Louise avenues at 5:15 a.m. It was reopened after repairs were completed about 3 p.m., said Jayne Suits of the California Highway Patrol.

Suits said the CHP received several telephone calls from motorists who said the potholes caused damage to their cars and led to several minor accidents.

Monday night, rushing rainwater collapsed a retaining wall in an Agoura Hills strip mall, forcing evacuation of a Chinese restaurant while officials determined whether the structure was threatened by rushing water eroding the parking lot. Two Los Angeles County fire companies worked for three hours, using sandbags to divert the rushing water, firefighter Roger Reding said.

“Had it continued . . . the building could have collapsed,” Reding said. City officials declared the building in the 30100 block of Agoura Road safe for occupancy Tuesday and the restaurant reopened for dinner.

In the Antelope Valley, the storm forced closure of public schools in seven of 10 districts--giving a free day to more than 30,000 high school and elementary students--and caused some confusion, school officials said.

Six districts canceled classes because the regional school bus agency, which carries a large share of the students, decided about 5 a.m. that the roads were unsafe for buses.

Ken McCoy, chief executive officer of the Antelope Valley Schools Transportation Agency in Lancaster, said the business usually carries about 20,000 students daily on 155 buses. “We had snow right here at the agency and the visibility was zero,” he said.

Classes were also canceled by Wilsona School District, which handles its own busing.

By 7 a.m., however, when youngsters usually begin arriving at schools in the area, the sun was shining and many streets had dried. But it was too late to reverse the closures, school officials said.

The agency received phone calls from some angry parents whose children were waiting in the cold at bus stops because they were not aware of the closures. There was also confusion because at least one radio station incorrectly reported that all schools were closed.

Three other elementary districts with about 15,000 children made their busing decisions later in the morning and kept schools open.

To the west, heavy snow and a mudslide forced closure of Interstate 5 between Lake Hughes Road in Castaic and Laval Road, north of the Grapevine, the CHP said. The mudslide closed the southbound lanes about 9 p.m. Monday, and up to 10 inches of snow forced authorities to close the northbound lanes at about 12:30 a.m. Tuesday.

Officer A.J. Torres estimated that a few hundred motorists were stranded in Castaic overnight. CHP officers at the Lake Hughes off-ramp were passing out Castaic Chamber of Commerce brochures early Tuesday informing travelers of local businesses offering discounts during the closure. The CHP began escorting vehicles along the northbound lanes at 10:10 a.m. Tuesday and opened all lanes at 11:35 a.m., said Lee Benjamin, a maintainence supervisor with the California Department of Transportation.

Caltrans crews used heavy construction machinery to clear the mudslide, which covered all or portions of the southbound I-5 just north of the Grapevine for one-quarter mile. They managed to open two lanes by 12:15 p.m. Tuesday, but the two remaining lanes were not expected to be clear until today, Benjamin said.