(Adds details on missing feared dead, changes dateline, previous ARLINGTON, Wash.)
By Jonathan Kaminsky
DARRINGTON, Wash., March 29 (Reuters) - Family and friends of 90 people still missing after a wall of mud flattened the outskirts of a rural Washington state town increasingly feared for the worst on Saturday as the governor called for a statewide moment of silence a week after the disaster.
"The number is so big and it's so negative. It's hard to grasp," said 66-year-old Bob Michajla, a volunteer who has been helping search part of the square-mile (2.6 square-km) debris field. "These are all friends and neighbors and family. Everybody knows everybody in this valley."
The number of people presumed dead grew to 27 on Friday as officials said one more body had been located in a field of muck and debris left when a rain-soaked hillside collapsed without warning last Saturday and engulfed dozens of homes on the outskirts of Oso, northeast of Seattle.
But the official death toll lagged at 17, based on bodies found, extricated and identified, a process complicated by the fact that some remains have not been found intact.
Authorities have located 10 more bodies in recent days but those are not yet included in the formal toll, and officials have repeatedly warned the number could soon rise substantially.
An estimated 180 people lived in the path of the landslide, and authorities said on Friday they were bracing for the worst for those still listed as missing in one of the strongest official acknowledgments that many of those lives may be lost.
"We always want to hold out hope but I think we have to at some point expect the worst," Snohomish County Executive Director Gary Haakenson told a Friday evening news conference.
"The crews are finding bodies in the field. It's a very slow process. It was miserable to begin with. As you all know, it's rained heavily the last few days. It's made the quicksand even worse," he said.
Governor Jay Inslee has called for a moment of silence on Saturday at 10:37 a.m. (1737 GMT), the moment the mudslide hit.
As families and friends wait for news, Facebook postings and other social media sites have served as ways to mourn and share memories of those presumed lost. A memorial page includes pleas for information on many of the missing, as well as prayers, condolences and offers of assistance.
"My next door neighbor lost his father and his stepmother. My daughter is friends with his granddaughter. I have other friends that have lost their entire families up there," said 50-year-old Brenda Roberson of nearby Arlington.
The plight of the Spillers family has garnered much attention. Postings on memorial web pages say Billy Spillers, 30, was at home with his four children when the hillside collapsed onto their home.
Four-year-old Jacob Spillers was pulled out alive but his sister Kaylee, 5, was found dead. Billy and his two other children are still unaccounted for. The mother was not at home and survived.
Linda McPherson, 69, a librarian died even as her husband was able to dig himself out, according to the Snohomish County Landslide Victims Memorial Page on Facebook, while a four-month-old girl and her grandmother were also among those who perished.
A volunteer searcher, Dayn Brunner, pulled the body of his sister, 36-year-old Summer Raffo, from the mud on Wednesday. The slide buried her in her car as she drove.
Authorities have in some cases allowed victims' relatives onto the site as the remains of loved ones are recovered, and a moment of silence is observed. Authorities have not pulled anyone alive from the rubble since the day the landslide hit, nor have they found signs of life.
Ron Brown, a county official involved in Snohomish County's search-and-rescue operations, said the debris field may end up being the final resting place for some victims who may be buried so thoroughly they cannot be found.
"That's going to be hallowed ground out there," he said.
John Farmer, 52, who lives east of the slide site, suggested at a community meeting on Friday that the site should never be rebuilt but turned into a park or other place of remembrance.
"A place where we can remember our loved ones, our neighbors, our families, our friends," Farmer said. (Additional reporting by Eric M. Johnson in Arlington, Wash.,; Carey Gillam in Kansas City and Steve Gorman and Dan Whitcomb in Los Angeles; Writing by Carey Gillam and Cynthia Johnston; Editing by Lisa Shumaker and James Dalgleish)