The town in Washington state buried by a monster mudslide that has claimed up to 24 lives so far was warned of the risk four years ago.
The landslip on Saturday destroyed dozens of houses in Oso, north-east of Seattle.
Authorities said the number of people still missing has dropped to 90 from 176 the previous day, as dozens of people were found to be alive and well.
The BBC reports the official death toll remained at 24 on Wednesday night, including eight bodies authorities say they have located but been unable to retrieve.
Additionally, at least 35 people are listed as having an unknown status, because authorities have been unable to determine whether they were in the area at the time of the mudslide.
Workers have been scouring the area for survivors and victims, using search dogs, helicopters and laser imaging.
A report commissioned in 2010 after a major slip in 2006 pinpointed the hillside overlooking the town as among the most dangerous in terms of possible collapse; but new home construction continued to be allowed.
A geological study in 1999 also warned of the potential for a catastrophic failure in the area. However, officials say the community was aware of the dangers.
Snohomish County emergency management department head John Pennington said townspeople felt safe in the small events.
"(But) this wasn't a small event. It was large, it was very catastrophic," he added.
A 54 metre wall of mud buried the town of Oso, north of Seattle, on Saturday.
As a fifth day of sarching came to a close, officials have said they have little expectation they will find anyone alive.
The catastrophe on Saturday destroyed about 30 houses, when a mudslide suddenly dammed a river and left a square-mile field of muck and debris in its wake. Part of a highway was also destroyed some 95km northeast of Seattle.
Survivors were last pulled alive from the mud on Saturday.
The operation was further complicated on Tuesday by heavy rain, as the workers were forced to contend with slippery mud, upturned nails, wreckage, and deep pits of water, Mr Hots said.
President Barack Obama has declared a state of emergency for Washington state.