NORTH SALT LAKE, Utah -- A family in this mountainside Salt Lake City suburb huddled late at night with neighbors and a local Mormon leader, praying in vain that a fractured ridge above their home would hold steady during a storm and prevent boulders and gravel from crashing through the back door.
Three generations of the Peruvian family awoke at dawn Tuesday to the sounds of snapping and rumbling as the rain-soaked swath of hillside crumbled above them. The six inside, including young children and their grandparents in their 70s, scrambled outside to escape danger.
After the family declined to talk with reporters, neighbors recounted the destruction from the landslide in the upscale community of North Salt Lake that came as severe thunderstorms hit Utah and Nevada. No one was hurt.
"We all sat on the porch and watched their house collapse," said Steven Peterson, 64, who lives in the house across the street. "It was very eerie and very frightening, and we knew the mountain was coming down."
Images showed the nearly 3,000-square-foot home on top of the driveway and landscaping rocks. Walls were ripped from the roof, and windows were blown out. A huge chunk of land measuring 400 feet by 400 feet, and 20 feet deep, was missing from the hill above.
Officials said three other homes faced immediate danger as storm clouds rolled in later Tuesday. Crews worked to move loose soil, build a barrier and drain pools to guard against more destruction.
Drivers paused on the road leading to the wrecked home, some taking photos, others gaping toward the slope in the city of about 17,000 people 10 minutes north of Salt Lake City.
"I think everyone's concerned it could slip some more," City Manager Barry Edwards told reporters. And if it did, how much damage it would cause wasn't immediately clear.
"It's hard to say whether or not it'd be catastrophic," said Greg McDonald, a geologist for the Utah Geological Survey. "It's not stable by any means."
The landslide forced the evacuation of 27 homes, and all but four families were expected to return by Wednesday when rainstorms pass, Edwards said. It's unknown when the other families will be allowed to go home. Some evacuees milled about in light rain Tuesday afternoon.
"You all should be ready to leave at a moment's notice," an emergency worker told them. "No matter where you are."
The threat of more storms came after flooding damaged about 100 homes Tuesday in Carbon County, southeast of Salt Lake City. In Nevada, flooding closed roads on the edge of Las Vegas and at Death Valley National Park, and the forecast called for more rain.
In North Salt Lake, officials had worried for nearly a year about cracked soil on the hillside above the houses. Geotechnical engineers and representatives from the home developer removed soil last fall to make the slope less steep and alleviate pressure, city engineer Paul Ottoson said.
The cracking reoccurred this summer, however, and the city hired a company to go back up to the hill to remove more soil. That work had just begun but was halted by this week's heavy rains, he said.
The city sent homeowners a letter this week recommending they protect their valuables. Some neighbors said they received the note a few days ago, while others said they received no such notice.
Further development on the hillside has been halted until the cause of the landslide becomes clear, Edwards said.
Eaglepointe Development, the company that has developed homes there extensively since 1999, said it conducted its work based on recommendations and approvals from the city and independent engineering companies.
Some neighbors questioned how such a seemingly vulnerable site could win approval for development. Heavy overnight rains Monday came as a surprise to everyone, Edwards said.
Angie MacDonald, 36, and her husband moved to the neighborhood in January with their twin 3-year-old daughters. They've worried since construction crews appeared on the ridge in recent months. At midday Tuesday, the family had not been evacuated.
"It's really scary, but it's not shocking either," MacDonald said. "It makes me wonder: Did we build in the right place?"
Associated Press writers Lindsay Whitehurst and Michelle Price in Salt Lake City contributed to this report.