Federal emergency officials toured tornado-ravaged areas in Northern Virginia yesterday, the neighborhoods' first step toward obtaining federal relief funds.

Walking gingerly around downed oak trees and peering into tarp-covered kitchens, Federal Emergency Management Agency workers visited a dozen or so of the most heavily damaged homes in Prince William County, focusing on whether they can be safely occupied. The team filled out checklists, took photographs of damage and defined locations using GPS plotters, said Ed Patterson, a FEMA worker who traveled from the agency's Texas office to assess Virginia's damage. The team did the same thing in Fauquier County yesterday.

The assessment will be used by Gov. Mark R. Warner (D) in deciding whether to ask for federal disaster funds to help property owners repair their homes. Warner's statewide declaration of a state of a emergency was unrelated to any official request for federal money.

Tropical Depression Ivan spawned more than 50 tornadoes across the state, including 17 that touched down, bringing winds of up to 206 mph. The storm and tornadoes destroyed a dozen homes, damaged 547 others and caused widespread crop damage, authorities said. Eleven injuries and one death -- in Campbell County -- were attributed to the storm, according to the Virginia Department of Emergency Management.

There is no set threshold of damage to qualify for federal disaster relief, and the scattered impact of Ivan on Virginia might hurt the state's chances for federal aid, officials said.

"A heavy concentration of damage generally indicates a greater need for federal assistance than widespread and scattered damage throughout a state,'' said Barbara J. Ellis, FEMA spokeswoman.

FEMA also takes into consideration the capacity of local relief organizations and whether an affected area is insured for damage such as that caused by flooding. Federal assistance usually provides direct aid to homeowners who need money to make repairs.

Virginia officials said they did not know when the assessment of damage in the state would be complete. In Fairfax County, where 51 homes were damaged and one was destroyed, officials said yesterday that FEMA had not contacted the county about an inspection.

If no federal assistance is received, Virginia homeowners would be able to apply to local charities for help, said Dawn W. Eischen, spokeswoman for the state Department of Emergency Management. Small businesses may be able to apply for low-cost loans and other government services open to them.

FEMA officials pulled up in front of Ed Henthorn's house in Brentsville yesterday morning. Henthorn, 50, said he had been outside grilling hamburgers Friday when a twister came through and he had to run for his basement. The storm rained down chunks of oak trees in what used to be his wooded yard, smashing both his garages and their contents, including a Honda Civic he had just put inside for safekeeping. All that was left was a small mountain of pink insulation, gray cinder blocks, white pegboard and blue plastic Wal-Mart bags. As a joke, he had placed a "For Sale" sign on the totaled Honda.

"I heard 'pop! pop! pop!' when it went through here," he said. "It was no more than 15 seconds. Then everything was sunny and quiet with no wind. It was bizarre, absolutely bizarre," he added, recalling that his burgers were still sizzling amid the wreckage.

The remnants of Ivan shook apples off trees in Virginia's Frederick County, 60 miles west of Washington, just as the harvest was beginning. Pumpkins and cabbages were lost in the eastern part of the state -- in addition to the rampant disease caused by heavy rains.

Steve Brim, an apple grower in Frederick County, said tornadoes touched down on both sides of his orchards last weekend. They ripped trees out of the ground and wiped out nearly his entire crop of golden delicious apples.

"It's pretty devastating. You work hard all year to grow these apples, and all of a sudden one storm takes it out," he said. But still, he considered himself fortunate. "We didn't have any deaths, the farmhouse is still intact, and trees can be replaced where lives can't be."

The random, almost pinpoint devastation of Friday's storm was evident in the Prince William neighborhoods that FEMA representatives toured yesterday. One side of the street would be picture perfect, while the other side looked as if it were the site of an impromptu logging operation.

Welcome to the Bechberger family's personal nightmare. Andrea and Mike Bechberger were sitting in the living room of their Brentsville split-level home when they heard and saw something terrifying coming right toward them.

Just as they made it to the basement, "I heard what sounded like the loudest clap of thunder I've ever heard," Andrea Bechberger said. Their roof opened, and tree limbs and a snowstorm of insulation dust rained down on them.

Mike Bechberger recalled his immediate reaction. "You can't print it," he said.

In the kitchen, Andrea Bechberger showed where a tree limb smashed through one of her cabinets, leaving all of her china in pristine condition but destroying every one of her everyday dinner plates.

It will take months to fix the house, and until then the Hampton Inn is their home. But considering what could have happened, the Bechbergers are looking on the bright side. Walking around in the rubble of what used to be her kitchen, Andrea Bechberger wore a T-shirt that said, simply, "Life is good.''

Staff writer David Cho contributed to this report.

Bill Lloyd of the Virginia Department of Emergency Management takes notes at a storm-damaged home in Prince William County.In the Brentsville area, Andrea and Mike Bechberger stand inside their home, whose roof gave way. They are living in a motel.Emergency management official Bill Lloyd listens to Ed Henthorn's account of tornado damage.