(Recasts with details on property damage; previous dateline OLYMPIA)
By Jonathan Kaminsky
ARLINGTON, Wash., March 24 (Reuters) - As many as 108 people remained listed as missing two days after a mudslide hit dozens of homes and killed at least eight people in Washington state, heightening fears that the casualty toll would grow well beyond the confirmed deaths.
Emergency management officials expressed doubt that anyone else would be plucked alive from the muck that engulfed dozens of homes when a rain-soaked hillside along State Route 530 near Oso, Washington, gave way on Saturday morning.
Meanwhile, concern lingered about flooding from water backing up behind a crude dam of mud and rubble dumped into a river by the slide in an area about 55 miles (90 km) northeast of Seattle.
"The situation is very grim," said Travis Hots, Snohomish County District 21 Fire Chief. "We're still holding out hope that we're going to be able to find people that may still be alive. But keep in mind we haven't found anybody alive on this pile since Saturday in the initial stages of our operation."
Several dozen homes in all were believed to have sustained some damage from the slide, John Pennington, director of the Snohomish County Department of Emergency Management, told reporters at a command post in the nearby town of Arlington.
More than 100 properties in all were swept by the cascading mud, 49 of which had a house, cabin or mobile home on them. At least 25 of those homes were believed to have been occupied year round, and 10 others were part-time or vacation homes, Pennington said.
The search for victims resumed under partly cloudy skies on Monday after treacherous quicksand-like conditions forced rescue workers to suspend their efforts at dusk on Sunday. Some workers, mired in mud up to their armpits, had to be dragged to safety.
A spokesman for the Snohomish County Sheriff's Office said eight bodies had been found by Sunday evening in the square-mile (2.6 square km) disaster zone of tangled debris, rocks, trees and mud. Another eight people were injured in the landslide.
On Sunday night, officials put the number of missing at 18 or more, but on Monday morning Pennington said various agencies had collected reports - some specific and others vague - of 108 people who remained unaccounted for after the disaster.
"The number is, I think no question, going to decline dramatically. But it is a number that we want to just go ahead and disclose and say, 'That's what we're working with,'" Pennington said.
HOPE FOR THE MISSING
The potential number of victims in harm's way was higher on a Saturday, with many people at home, than on a weekday when more residents would have been at work or school, Pennington said. He added that search teams were also trying to account for an unspecified number of construction workers who were in the area and motorists who were driving by at the time.
But authorities were hoping many of those reported as missing will turn out to be survivors who were either double-counted or slow in alerting loved ones and local officials as to their whereabouts.
The slide in the foothills of the Cascade Mountains along the North Fork of the Stillaguamish River piled mud, boulders and rubble up to 15 feet (5 m) deep in some places.
It blocked the flow of the river, backing up water behind a natural dam left in the stream's channel that caused flooding of seven homes upstream of the slide, Pennington said.
"The bad news is that the water continues to rise and homes are inundated up to the eaves in many cases," he said. "If there is a silver lining in that event ... it is that it is a slow, methodical rise. You can see the danger."
Authorities said as the volume and pressure of water behind the dam continued to build, there was a chance that additional downstream flooding and mud flows could be unleashed.
Water from the river was trickling through the side of the debris plug and creating a new stream channel, prompting authorities to post observation teams downstream to watch for signs of danger, state emergency management officials said.
Hots said Monday's search for victims would incorporate the use of aircraft, teams with search dogs and special electronic equipment.
"Also, the Washington State Department of Transportation is going to have heavy equipment out there to clear mud out of the way so that we can continue to search those areas," he said.
Washington state Governor Jay Inslee said the regional head of the Federal Emergency Management Agency issued a verbal declaration that would allow for immediate federal disaster assistance to deal with the aftermath of the slide. (Writing by Steve Gorman; Editing by Cynthia Johnston, Cynthia Osterman and Richard Chang)