Three mountain avalanches killed a skier and left as many as four others missing Friday as California strained under nearly a week of snow and rain.

One avalanche struck Friday afternoon at Wrightwood in the snow-laden San Gabriel Mountains. Michael McKay, a 23-year-old employee of the Mountain High ski area, was pulled from the debris, San Bernardino County coroner's office said. He died at a hospital later that afternoon, a hospital spokeswoman said.

As night fell, searchers were still looking for another person who was missing after a second avalanche about a half-mile from the first, on national forest land. A third avalanche also was reported and as many as three people were believed to be missing, said Los Angeles County sheriff's Deputy Aura Sierra.

"I'm sure that the avalanches are due to the amount of snow that has fallen over the past several days," said Tim Wessel, division chief for the San Bernardino County Fire Department.

The avalanches were outside Mountain High's boundaries. The resort, which was closed by high winds a day earlier, remained open.

An avalanche advisory was issued for the ski area at nearby Mount Baldy, a 10,000-foot peak about 40 miles east of Los Angeles, and the lifts there were closed, Angeles National Forest spokesman Stanton Florea said.

The avalanches followed days of stormy weather throughout California as the southern half of the state braced for a major storm that was expected to pour several more inches of rain beginning Saturday night.

"It's going to be a dumping," said Bill Hoffer, a spokesman with the National Weather Service.

Elsewhere, utility crews repaired electrical outages while highway crews worked to keep mountain routes open.

Nearly 11,000 homes and businesses throughout Southern California were without electricity, including about 6,700 Los Angeles Department of Water and Power customers.

A 40-mile stretch of Interstate 5 over Tejon Pass north of Los Angeles reopened after being closed for two days and stranding hundreds of drivers. Highway Patrol officers escorted cars over the summit.

"If it becomes snowy or icy, they'll close down the freeway at once," Officer Miguel Leuvano said.

A Metrolink train on a morning commute from Ventura County to Los Angeles through a narrow, rocky gorge hit a slide of mud and rocks on the tracks. The stranded train had to be pulled by another train to the next station and four other trains had to be halted, delaying 2,000 passengers for 2 1/2 hours, said Metrolink spokeswoman Denise Tyrrell. No injuries were reported.

In the Woodland Hills area of Los Angeles, mud washed down a naked hillside below a construction site and flowed into two homes.

"We have a flooded kitchen, flooded laundry room, driveway had a foot of water in it," a resident told KCAL-TV.

Southern California rainfall totals from Monday afternoon through 4 p.m. Friday included 9.43 inches at Opids Camp in the San Gabriel Mountains above Pasadena and 8.15 inches at Gibraltar Dam in Santa Barbara County.

Downtown Los Angeles got 3.43 inches during the week, more than fell in the entire previous rain season.

Rain caused delays of up to two hours Friday morning at San Francisco International Airport, and officials expected the delays to continue.

"We're on a ground-delay program from 9 a.m. to midnight," said airport duty manager Linda Perry. "It is raining very hard, so we are seeing delays for the arrivals and subsequent departures."

Off the coast of Corona Del Mar, Orange County harbor patrol deputies rescued a cat from a moored 42-foot boat just before it went down in heavy seas, said sheriff's spokesman Jim Amormino.

A new storm system was expected to arrive Saturday night and dump several more inches of rain through Sunday.