Created: 03/23/2014 1:59 PM KAALtv.com
ARLINGTON, Wash. (AP) - Authorities in Washington state say it's too dangerous to send rescuers into a mudflow that is "basically like quicksand."
The mud was so thick and deep that searchers turned back last night after attempting to reach an area where voices had been heard crying for help.
Officials say about 18 people are unaccounted for after yesterday's massive mudslide that killed at least three people and injured several others.
Authorities say the slide wiped out one neighborhood of 28 to 30 homes, and blocked about a mile of State Route 530 near the town of Oso, about 55 miles north of Seattle.
The mud was reported to be about 60 feet deep in some areas.
As authorities try to determine how to get responders on the ground safely, helicopters will be flying over the area looking for people who may have been able to get out on their own and any other signs of life.