SEATTLE -- People living in the path of a deadly Washington state landslide had virtually no warning before a wall of mud, trees and other debris thundered down the mountain. Some of the homeowners didn't even know the hillside could give way at any time.
Unlike the warning systems and elaborate maps that help residents and officials prepare for natural disasters such as floods and hurricanes, there's no national system to monitor slide activity and no effort underway to produce detailed nationwide landslide hazard maps.
The U.S. Geological Survey doesn't track or inventory slide areas on a national scale, despite an ambitious plan to do so more than a decade ago when Congress directed it to come up with a national strategy to reduce landslide losses.
That's left states and communities to put together a patchwork of maps showing landslide hazards. In some cases, they are discovering that more buildings than previously thought are sitting on unstable ground. Even then, that information may not make its way to property owners.
Building a nationwide system is now possible with new technology, experts say, but would require spending tens of millions of dollars annually and could take more than a decade to complete with the help of states and cities.
So far, however, there has been little public outcry for faster, concerted action.
"No one has pushed it, and it hasn't been a priority," said Scott Burns, a geology professor at Portland State University. "It's costly to monitor it, and we don't want to pay for it."
He added, "Now they're seeing these large disasters and saying this is important."
The challenge, experts say, is that many landslides are inactive or cause consistent low-level damage, while big, destructive landslides happen only sporadically and don't cause the type of spectacular devastation hurricanes, earthquakes or tornadoes do -- so they often don't get the same attention or resources.
Despite this, landslides have exacted a toll in all 50 states, causing 25 to 50 deaths a year and up to $2 billion in losses annually. The last national map -- which shows high landslide risk areas in the Appalachians, the Rockies and along the West Coast -- was published in 1982, but it is outdated and lacks detail.
The lack of attention on landslides comes as experts say increasing numbers of people are moving farther out from cities and suburbs -- or onto previously uninhabited slopes within them -- and are more likely to come face to face not just with the views they sought but also with nature's destructive forces.
Development on vulnerable land can disturb soil, put too much weight on slopes or increase soil moisture, whether it is from runoff or a prolific sprinkler system.
Rescue crews in Oso said Sunday that many of the dogs that have been essential in the search for victims will take a two-day break. Days of sniffing through cold, soupy mud and nearly nonstop rain have taken their toll on the animals, and officials say dogs can lose their sensing ability if they work too long.
"The conditions on the slide field are difficult, so this is just a time to take care of the dogs," said Kris Rietmann, lead spokeswoman for the team working on the eastern portion of the slide.
Dogs from the Federal Emergency Management Agency, more recent arrivals on the scene, will continue working, said Heidi Amrine, another spokeswoman for the operation.
Engineers were watching for any material sloughing off the landslide area, making sure that a weekend of torrential rainfall doesn't displace more land.
Meanwhile, many residents attended church services for solace ahead of another week of recovery efforts.
Robin Youngblood, whose house in the foothills of the scenic North Cascades was crushed in the landslide, said Snohomish County officials did not inform her about the dangers of the hillside.
"They knew that this mountain was unstable and they let people build there," she said. "This shouldn't have happened."
The Associated Press' Jonathan J. Cooper and Lisa Baumann contributed.