Startled deputies standing on mud-soaked Highway 101 on Monday looked up to the hills when they heard a booming "crack."

The explosive sound was the only warning. Within seconds, the entire top of the bluff above the community of La Conchita rippled down the slope, crushing homes and people in its path.

"It was just instant; there was no time to run for cover," said Sheriff Bob Brooks. "Even those residents watching and ready to go couldn't get very far."

A sergeant on the scene directing the evacuation of stranded motorists on Highway 101 saw the wave come down and overtake people trying to run, Brooks said. "It was a terrible thing to see."

Everyone was looking for answers Wednesday, from county supervisors to shellshocked residents who are temporarily transient. Why so many dead? Why did no one order an evacuation as record rains saturated the unstable hillside for four days? And what will become of the beachside community?

Daily updates planned

County officials held a meeting Wednesday morning to update residents -- the first of what they hope will be daily briefings as rescue turns to recovery and cleanup begins. Supervisors were briefed as well by Brooks and County Fire Chief Bob Roper in the afternoon.

Tearful and weary survivors of La Conchita fired off questions about topics ranging from property taxes to rebuilding to why they weren't evacuated before the landslide destroyed 13 homes and killed at least 10 people.

One resident asked, "Are we safe there now?"

James O'Tousa, a geologist for the county contracted to monitor La Conchita bluffs after the 1995 landslide, said, "No, you're not. I anticipate more slides where you are."

O'Tousa is studying the stability of the hillside and will provide a report to supervisors and county officials within a week to 10 days. They will use that report as well as other assessments to decide the next steps.

Supervisor Kathy Long, chairwoman of the Board of Supervisors, said condemnation is one option, as it was in 1995. Instead, the county put restrictions on any new building. She said the Federal Emergency Management Agency has condemned property along the Mississippi River because it's cheaper than rebuilding.

If that were the case, the county would seek court approval to legally seize the property but would have to pay for it. Land values may decline significantly after a disaster, County Assessor Dan Goodwin warned residents.

Study would cost millions

To get a full picture of the threat, supervisors would have to pay for a full-scale engineering study that would define ways to fortify the bluffs, Brooks said. However, the projected cost of such a study is $2.5 million to $4 million. Fixing the hill could cost as much as $45 million.

Annelle Beebe said La Conchita has always been an afterthought to county officials, contrasting it with the attention she sees wealthy Malibu residents getting when the hillsides fall in Los Angeles County.

"La Conchita always gets forgotten," she said at the residents' meeting. "It's very, very frustrating."

They wanted to know why they weren't evacuated, when and if they could return to their homes, whether building fees would be waived, and what taxes they would owe.

But mostly residents wanted to know if the tragedy could have been prevented. Several asked whether enough had been done to monitor the bluff during the heavy weekend rains.

"That morning when the river flooded, who made the decision not to evacuate?" asked resident Vera Long. "We were told we couldn't leave."

No warning of slide this time

In a later interview, Roper said there was no indication the mountain was going to fail, unlike the 1995 landslide that destroyed homes but took no lives.

"In 1995, residents notified us" the hillside was beginning to slip, Roper said. "We had time ... all agencies were brought in and no one was evacuated at that time."

This time, emergency offcials were busy reacting to disasters cropping up all over the county. Brooks said daily meetings were held to decide which threats -- mudslides in Piru, swelling rivers overflowing their banks -- should be handled first.

Early Monday morning, Highway 101 was shut down at the Ventura River and just north of La Conchita, stranding 150 motorists because of flooding, Brooks said. That effectively trapped the residents in the neighborhood, keeping kids home from school and adults home from work.

"Virtually every meeting, La Conchita was always a subject of discussion," Brooks said. "But based on what our experts told us, the ground was not moving. We had to prioritize. We only have so many resources and we had emergencies that were already happening."

Both Supervisor Judy Mikels and Long said there was nothing the county could have done to prevent the tragedy.

"It's like, 'Can you prevent an earthquake?' " Mikels said. "No. According to early reports, this was a catastrophic failure of the mountain. When a mountain lets go, there's no warning that's going to happen."

The homeowners also had personal responsibility because they knew where they were living, she said. La Conchita is designated a geologic hazardous area and notices are posted on each home.

"They were forewarned they're in a slide area," Mikels said. "It's their responsibility. We are ultimately responsible for the choices we make."