(CNN) -- Rescue efforts continued Friday, nearly a week after a deadly landslide smothered a square-mile of land in rural Washington state, though no survivors have been found for days.
The death toll on Friday officially stood at 17, but at least seven unidentified bodies had been found but not yet recovered.
Nearly 90 people are missing, and officials expect the death count to jump dramatically on Friday.
"That number is going to likely change very, very much (Friday) morning," Fire District Chief Travis Hots said.
Despite the grim outlook, rescuers continue to tread carefully and avoid using heavy machinery where survivors may still be found.
"As far as I'm concerned, we're still in rescue mode," Hots said Thursday evening. "I haven't lost hope yet. ... That chance is very slim, but we haven't given up yet."
Saturday's collapse dragged several homes downhill with it, scattering their contents among hundreds of acres of earth and smashed trees.
"Anything that anyone would have in a neighborhood is now strewn out here," said Steve Mason, a Snohomish County fire battalion chief. Some houses "look like they've been put in a blender and dropped on the ground, so you have basically a big pile of debris."
The landslide near Oso, about 60 miles northeast of Seattle, has turned many lives upside down.
While some families cling to the hope that their loved ones have survived, others -- like Rae Smith, whose daughter Summer Raffo was driving through the area when the slide hit -- are in mourning.
"My heart is broken. It's broken," Rae Smith said.
Pointing out homes on a map, volunteer rescuer Peter Selvig noted the seemingly random nature of the fatalities.
"This guy lived and his wife died. ... We were on the school board together for about 30 years," Selvig said.
More rain made the mud worse Thursday, slowing the search, rescuers reported.
Senior Airman Charlotte Gibson -- part of an Air National Guard squadron assisting the search -- said rescuers "fall in about waist-deep in some areas," knee-deep in others.
"Just walking through it, it's almost impossible," Gibson said.
And as bad as the conditions are, the scale of the devastation is worse. Master Sgt. Chris Martin told reporters, "I don't think anything could prepare you for what you see out there."
The area affected in the most recent calamity has been hit before, in 1951, 1967, 1988 and 2006. Daniel Miller, a geomorphologist who co-wrote a report in 1999 for the Army Corps of Engineers that looked at options to reduce sediments from area landslides, said that none of these events resulted in deaths, though at least the most recent one damaged houses.
This history, along with erosion from Stillaguamish River and worries about overlogging, prompted some mitigation and other efforts. A 2010 plan identified the area swept away as one of several "hot spots," John Pennington, Snohomish County's emergency management director, told reporters Wednesday.
The county had been saturated by "amazing" rains for weeks that made the ground even less stable, Pennington said. Then there was a small, recent earthquake that may or may not have exacerbated the situation.
But he said no one anticipated the scale of Saturday's landslide: "Sometimes, big events just happen." And he said residents knew the area was "landslide-prone" -- an assertion one of them challenged.
"Nobody ever told us that there were geology reports," Robin Youngblood told CNN's Anderson Cooper. "This is criminal, as far as I'm concerned."
Determining whether the human toll from this disaster could have been abated is a key question, but one best answered another day, Gov. Jay Inslee has said. For now, the focus is on the ground -- and in the air -- scouring through the rubble.
And once again, Mother Nature is making things complicated. While Snohomish County reported late Thursday afternoon that water levels on one side of the slide had fallen 2 feet -- a "big help for rescuers," the county tweeted -- the National Weather Service forecasts more rain Friday and beyond, which will complicate rescue efforts.
For that reason, rescuers are keeping an eye on the weather even as they sift through silt, wood and rubble, according to Snohomish County Public Works Director Steve Thompson.
"Right now there's no risk of further slides, but we're watching the rain," Thompson said.