US mudslide deaths to rise substantially
28 March 2014, 11:30
Darrington - Washington state authorities said on Thursday that the number of mudslide fatalities will go up substantially in the next two days.
Ninety people are confirmed missing from the Saturday morning mudslide 90km northeast of Seattle.
Sixteen bodies have been recovered, but officials say at least nine more had been found as of Wednesday night.
Snohomish County District 21 Fire Chief Travis Hots said on Thursday that officials are not going to count additional recovered victims until the medical examiner's office has caught up with the recovery effort.
"In the next 24 to 48 hours, as the medical examiner catches up with their work, you're going to see these numbers increase substantially," Hots said.
Scores of people once thought missing in the mudslide have turned up safe, but that provided little relief to rescuers who are tasked with bringing closure to the relatives and friends of those who have not been found.
Seismic signals showed there were two major slides about four minutes apart during Saturday's disaster and afterward smaller slides continued for days, University of Washington researchers said.
The landslide moved with surprising speed, said Ralph Haugerud, a USGS research geologist at the University of Washington.
"Not very many move this fast," he said Thursday. Typical landslides in the Nooksack Valley "crept down the hill".
The vibration of falling can cause a landslide to turn into a debris flow that moves like water.
"My hunch is the slide may have dropped farther than many, and as it did it liquefied," Haugerud said.
The study of seismic signals showed no earthquake triggered the slide, said Kate Allstadt, a university researcher. Landslides are harder to study than earthquakes because the signals are less clear and don't travel as far, said Allstadt, who used seismology tools to research landslides for her doctorate.
Hope of a miracle discovery of a survivor has faded as the search entered its sixth day on Thursday, but Hots said crews are going to exhaust all options in the effort to find somebody alive in the devastation.
"My heart is telling me I'm not giving up yet," he said. "If we find just one more person alive, it's all worth it to me."
Trying to recover every corpse would be impractical and dangerous.
The debris field is about 2.5km² and 9m to 12m deep in places, with a surface that includes quicksand-like muck, rain-slickened mud and ice. The terrain is difficult to navigate on foot and makes it treacherous or impossible to bring in heavy equipment.
To make matters worse, the pile is laced with other hazards that include fallen trees, propane and septic tanks, twisted vehicles and countless shards of shattered homes.