LOS ANGELES (CNN) -- Torrential rains moved walls of rock and mud Friday in South California, burying homes in one neighborhood, closing a coastal highway, and prompting evacuations of foothill communities imperiled by landslides.
The damage marked the second day of a fierce storm slamming the Pacific Coast that, in California, served to trade one natural disaster for another, namely the state's record drought of the past three years.
At a minimum, the biggest storm in years slaked the dry earth, but it is coming at a high price for many people.
Southern California Edison reported more than 18,000 customers without power in 119 outages late Friday morning, down from earlier count of 35,000 customers.
Mudslides swarmed or threatened homes near recent hillside fires.
Eight homes in the Camarillo Springs area saw "significant damage" when a mudslide crashed into houses and piled rocks almost as high as roof lines, according to authorities KTLA.
An elderly couple needed to be rescued after they stayed in their home despite a voluntary evacuation order and suddenly found water and earth plowing into their bedroom.
"It just came pouring in, so I told my wife just stay in bed," the man told the affiliate after he was rescued. "I could just feel the mud... there must be 3 or 4 feet of mud in there."
Firefighters carried the couple to safety, uninjured. "I'm OK," the man told the station.
Swift water recovery and rescue
Firefighters in Orange County conducted a rescue in the swift waters of a flood channel in Garden Grove.
The man being rescued, however, appeared to be dead and was stuck on a central pillar of a ditch tunnel, said Lt. Ben Stauffer of the Garden Grove Police Department.
Detectives were investigating the individual's identity and the circumstances of the apparent death, Stauffer said. A pedestrian discovered the person in the channel, he said.
Meanwhile, Los Angeles firefighters rescued one person from the Los Angeles River and was attempting late Friday morning to rescue a second person, the fire department said.
Residents piled sandbags outside their homes near where the so-called Colby Fire scorched 1,952 acres in Angeles National Forest in January near Glendora and Azusa.
Glendora imposed a mandatory evacuation on an unspecified homes in the Colby Fire Impact Area. Meanwhile, Azusa issued a voluntary evacuation order for its residents in the burn area, CNN affiliate KABC reported.
Meanwhile, flooding, rocks and mud closed parts of the scenic Pacific Coast Highway from Monterey County down to Huntington Beach, the California Department of Transportation said.
Northern California recovering
The Bay Area and other pockets of California began returning to normal Friday after the tempest doused exceptionally drought-stricken California with water, causing street and moderate river flooding, and produced blizzard-like conditions in the Sierra Nevada mountains.
The storm took a deadly toll further up the coast.
Falling trees killed two people in Oregon and left a third seriously injured.
At one point, the combination of powerful winds and battering rains knocked power out to 225,000 customers from Northern California to the Canadian border. That number had fallen to almost 185,000 by late Thursday, according to a CNN tally.
As of Friday morning, the Pacific Gas and Electric Company -- the biggest utility in Northern California -- tweeted that "93% of the customers who lost service have power restored." Public transportation in the Bay Area was also moving much better Friday morning, after the storm prompted the halting of ferry and MUNI cable car service.
In Oregon, a homeless man, Phillip Crosby, died when a tree fell on the tent where he was sleeping, said the Jackson County Sheriff's Office. Crosby's 18-year-old son, Alexander Crosby, tried to revive his father, the Sheriff's Office said.
The tree was 8 to 10 inches in diameter and partially struck Phillip Crosby across the arm and chest, his son, who is also homeless, told officials.
A young boy died in Portland, when a falling tree struck a car he was traveling in, said Portland Fire and Rescue spokesman Lt. Damon Simmons. The child was pronounced dead at the scene.
A woman driving behind that car swerved and struck a second tree. She was taken to a hospital with life-threatening injuries, Simmons said.
The rain intensity in Northern California on Thursday was reminiscent of a tropical shower in some places, a biblical deluge in others.
Nearly 2.5 inches doused the San Francisco Bay Area, but north of there, just beyond wine country, 14.6 inches washed down on the Petrified Forest.
The rain will put a dent in a historic three-year drought that has sapped reservoirs, threatening farmers and driving up food prices.
"We need it, but I wish it would come more evenly spread out, instead of all in one night," said Kim Cheadle, who commuted from Marin County but found her San Francisco office building closed Thursday.
Heavy rains flooded low-lying areas and streets, and gummed up air travel, and high winds with isolated gusts up to 80 mph roughened waterways with high surf.
CNN iReporter Brandon Ball said he flew into San Francisco on Thursday morning and got stuck in a cab on U.S. Route 101.
"Right before approaching Bayshore Boulevard, the freeway was completely flooded on both the north and southbound side, with multiple cars stuck in the water," the Los Angeles resident said.
There were isolated reports of roof damage in California and Oregon, and the wind drove in waves that broke at around 20 feet in height all along the northern half of the West Coast.
A winter storm warning projected up to 3 feet of snow along the Sierra crest by Friday, the weather service said.
An 'atmospheric river'
Much of this moisture, at least along the California coast, comes from an "atmospheric river," a band of heavily moist air that split off from a larger such band in the tropics.
It's as if a river in the sky spilled its banks, sending a new tributary 250 to 400 miles wide northeastward to California.
Such atmospheric river drenchings in California are rare but also normal and necessary, the National Weather Service said. They're how the parched state gets up to 50% of its annual rainfall.
The current "river" has been around since late November and already soaked the state last week.
CNN's Greg Botelho, Dave Alsup, Topher Gauk-Roger and Erica Henry contributed to this report. Ben Brumfield wrote and reported from Atlanta, and Michael Martinez from Los Angeles. Dan Simon and Sara Weisfeldt reported from San Francisco.