By P. SOLOMON BANDA, LISA BAUMANN, DONNA GORDON BLANKINSHIP and PHUONG LE
The Associated Press
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As search efforts stretch into the third day, here are five things to know about the catastrophe:
VOICES CALLING OUT: Late Saturday, rescuers heard people yelling for help but were unable to reach anyone.
The soupy, quicksand-like mud was so thick and deep that searchers had to turn back.
When crews were able to get back onto the debris field Sunday, they found only more bodies. "We didn't see or hear any signs of life," Snohomish County Fire District 21 Chief Travis Hots said Sunday evening.
THE DEAD, THE MISSING, THE DAMAGE: The death toll is at least 14. On Monday, authorities said 176 names were on the list of people reported missing or unaccounted for, but they cautioned that figure likely would go down.
Dozens of structures in a riverside community were destroyed, including many full-time homes.
BIG WALL OF MUD: The 1-square-mile mudslide that struck late Saturday morning was described as a "big wall of mud and debris."
It was reported to be 15 feet deep in some areas. It blocked a portion of State Route 530 near the town of Oso, about 55 miles north of Seattle.
FLOOD WORRIES: The slide also crashed into the North Fork of the Stillaguamish River, blocking it.
The river continuing to back up, officials said.
Authorities said Monday that at least seven homes are now flooded, and more flooding is expected.
POSSIBLE CAUSES: Snohomish County Department of Emergency Management officials say the area has a history of unstable land.
A slide also happened there in 2006.
Authorities believe the latest slide was caused by recent heavy rainfall that saturated and destabilized the ground.
David Montgomery, an earth and space sciences professor at the University of Washington, said these deep-seated slides tend to occur from rainfall over months or seasons.
"This was a big deep one, a giant slump," he said.
In the struggle to find loved ones, family members and neighbors used chain saws and their bare hands to dig through wreckage that was tangled by the mud into broken piles.
Late Monday, the list of potentially missing people topped 176 following the disaster Saturday about 55 miles northeast of Seattle.
But Snohomish County Emergency Management Director John Pennington stressed that authorities believed the number included many duplicate names.
"The 176, I believe very strongly is not a number we're going to see in fatalities. I believe it's going to drop dramatically," he said.
The number of those possibly missing grew dramatically from an estimated 108 earlier Monday.
But Pennington said the list was compiled from information provided by the public, and officials were trying to cross off reports that likely described the same person. The list included construction workers who were working in the area and people just driving by.
The lack of definitive information two days after the massive slide destroyed a cluster of homes at the bottom of a river valley ratcheted up anxieties.
"The situation is very grim," Snohomish County Fire District 21 Chief Travis Hots said, stressing that authorities are still in rescue mode and are holding out hope.
But he noted: "We have not found anyone alive on this pile since Saturday."
Snohomish County sheriff's spokeswoman Shari Ireton said Monday afternoon that search and rescue crews discovered an additional six bodies, bringing the number of confirmed fatalities to 14. The slide critically injured several others.
About two dozen houses were flattened, and the debris blocked a mile-long stretch of state highway near Arlington.
Cory Kuntz and several volunteers worked Monday with chain saws to cut through the roof of his uncle's house, which was swept about 150 yards from its previous location.
Kuntz said his aunt, Linda McPherson, was killed. He and the others pulled out files, his aunt's wallet and a box filled with pictures and slides.
"When you look at it, you just kind of go in shock, and you kind of go numb," he said, adding that there were more people out helping Sunday. On Monday, they couldn't get through roadblocks.
"They are all eager to get down here, but unfortunately they can't. It just shows how tight this community is," he said.
Doug Reuwsaat, who grew up in the area and was also helping in the search, said authorities had told people to stay away.
"We're related to a lot of these people from around here. So that's why we're here," he said.
The mudslide struck Saturday morning, a time when most people are at home.
Of the 49 structures in the neighborhood, authorities believe at least 25 were full-time residences.
Monday's search included aircraft, dogs and heavy equipment.
Frustrations were growing as family members and neighbors waited for official word on the missing and the dead. Elaine Young and her neighbors uncovered several bodies Sunday and had to contact authorities to get them removed.
They also found a chocolate Labrador named Buddy alive, and helped pull the dog from the rubble, leading her to wonder if other survivors could be out there, desperate for help.
"If we found a dog alive yesterday afternoon that we cut out of a part of a house, doesn't that seem that maybe somebody could be stuck up under part of a house and be alive too?" asked Young, whose home survived the slide but was on the edge of the devastation.
Authorities believe Saturday's slide was caused by recent heavy rains that made the terrain unstable.
From the beginning, rescue crews on the ground have faced dangerous and unpredictable conditions as they navigated quicksand-like mud that was 15 feet deep in some places. Some who went in got caught up to their armpits in the thick, sticky sludge.
The threat of potential flash floods or another landslide also loomed over rescuers.
On Monday, some crews had to pull back because of concern that a hillside could shift. Snohomish County Public Workers Director Steve Thomsen said geologists checked the area and decided that "right now it's stable."
Retired firefighter Gail Moffett, who lives in Oso, said she knows about 25 people who are missing, including entire families with young children.
"It's safe to say I'll know everyone affected or who they are," Moffett said. "There's so much pain going on in the community right now."
Among the injured were a mother and her baby. Amanda Skorjanc, 25, was in satisfactory condition at Harborview Medical Center in Seattle, spokeswoman Susan Gregg said.
Her son, 22-week-old Duke Suddarth, remained in critical condition and was improving, Gregg said. Three other men were in serious condition.
The spirits of search-and-rescue teams were raised late Saturday when they heard cries for help from the flotsam of trees, dirt and shattered wood. But no one else has been found alive.
The slide blocked the North Fork of the Stillaguamish River, which is continuing to back up, officials said. Authorities said Monday at least seven homes are now flooded, and more flooding is expected.
Frequent, heavy rain and steep geography make the area prone to landslides. Less than a decade ago, another slide hit in the same general area.
On Monday, President Barack Obama declared an emergency, ordering federal aid for the struggling community and federal agencies to coordinate relief efforts.
Barbara Welsh went to Monday's news briefing in Arlington to get more information. She said she has not seen her husband, William Welsh, since Saturday, when he went to help someone in Oso with a water tank.
Bruce Blacker, who lives just west of the slide, doesn't know the whereabouts of six neighbors.
"It's a very close-knit community," Blacker said as he waited at an Arlington roadblock before troopers let him through.