US mudslide death toll to increase 'substantially'

DARRINGTON, United States- Emergency managers said they were close to announcing a "substantially" higher death toll from the monster US landslide that killed at least 16 and left 90 missing.

The confirmed number of dead stands at 16 with at least eight more bodies believed located after the massive mudslide crashed onto the town of Oso in the northwestern US state of Washington.

But Snohomish County District 21 Fire Chief Travis Hots said on Thursday bodies were not being included in the official death toll until they had been recovered and "medical officers have done their difficult work."

"That number is going to be likely change very very much tomorrow morning," Hots said late Thursday, after warning that the death toll would rise "substantially."

A total of 49 dwellings in the rural town were hit by the square-mile (2.5-square-kilometer) wall of mud, rocks and trees, which also destroyed part of a highway about 60 miles (95 kilometers) northeast of Seattle.

Physically and mentally difficult

More than 200 rescue workers have been working in grim conditions for the last five days. A few survivors were found immediately after the mudslide, but none since Saturday.

Rescue volunteer Kraig Wenrick said the task was both physically and mentally difficult, as they dug "right into the heart" of the landslide mass.

"That's what we've got to prepare our minds for... finding bodies. If they're there," he told AFP in Darrington, the town on the east side of the slide.

"Ultimately we'd like to find survivors," he said, but added: "It's getting hard to know."

Emergency officials have come in for criticism as the rescue operation drags on, with some locals frustrated that they have not been allowed to help in the search.

Authorities also defended themselves against suggestions they could have given more warning about the landslide. A 2010 report following a 2006 mudslide identified the Oso region as facing a major risk.

Quake didn't trigger landslide

The cause of the landslide remains unclear. Some say recent rain increased the risk of a slide on the saturated hillside, while The Seattle Times said long-term logging allowed on the plateau above may have made the area more unstable.

The US Geological Survey dismissed a suggestion, mentioned by emergency management chief John Pennington earlier in the week, that a small earthquake could have triggered it.

"There are no earthquakes or other local seismic events on the records around the time of the landslide," said a USGS statement.

Fire chief Hots said workers have not given up hope of finding survivors, even if the chances diminish by the day.

"If we find one more person alive, to me that's worth it," he said.

Clay balls 'size of ambulances'

But the scale of the disaster was staggering, when viewed up close.

"You just can't fathom what we're up against... until you get out there and see the lay of the land," Hots said.

"You've got clay balls the size of ambulances that have rolled off that hill and smashed everything that they've come into contact with."

In terms of determining the death toll, Tom Minor of the Federal Emergency Management Agency (FEMA) compared the situation to the 9/11 attacks or the 1995 Oklahoma City bombing which killed nearly 170 people.

"Will we ever get an accurate number? It took us weeks to get an accurate number in Oklahoma City. And I'm not sure we have an accurate number out of the World Trade Center," he told reporters.

Emergency managers have held twice-daily briefings since the weekend. The next one is due at 9.00 am (1600 GMT), Friday.