After Peggy Harrah's yellow Cadillac was smashed in front and back Monday in one of two chain-reaction pileups on foggy Afton Mountain, Va., people were urging her to get out of the car. It was safer, they shouted, as other vehicles crashed behind her.

Harrah, 43, a mother of two from Beckley, W.Va., scrambled out of the Cadillac into the dense mist and was hit almost immediately by still another vehicle that slammed into the side of her car. She was one of two people killed in the collisions on Interstate 64 that involved 54 vehicles, injured 40 people and will be remembered as the worst in Virginia traffic history.

"Everybody was saying, 'Get out. Get out before other cars come,' " Harrah's minister, the Rev. Bill Parker, said yesterday after a conversation with Harrah's relatives who were slightly injured in the accident.

Virginia State Police said yesterday that each of the deadly series of collisions -- one in the westbound lanes involving 44 vehicles and the other in the eastbound lanes involving 10 -- started when a vehicle braked or swerved to avoid hitting other vehicles in the nearly impenetrable fog on Afton Mountain, 140 miles southwest of Washington near Waynesboro in the Blue Ridge Mountains.

In the westbound lanes about 10:45 a.m., the first chain reaction began after the driver of a pickup truck swerved to avoid hitting a slow-moving vehicle ahead of him and lost control, according to state police Sgt. E.R. Kiser. A 77-year-old man, Robert W. Welsh, who has residences in Spring Hill, Fla., and Marquette, Mich., was in the 20th car in the pileup and died of an apparent heart attack, Kiser said. Welsh, a former Arlington resident, was an airplane mechanic at National Airport until he retired in 1975.

The second chain reaction occurred minutes later in the eastbound lanes when a car braked for a rescue vehicle that had stopped to help the victims of the first accident, Kiser said. Harrah's Cadillac was the third vehicle in that pileup.

Kiser, who is acting as the lead accident investigator for the state police, said he does not know whether anyone will be charged in the accidents.

Authorities were still trying to determine yesterday whether a broken patch of fog lights along I-64 contributed to the collisions. The Virginia Department of Transportation has said that a 1,500-foot string of fog lights, which are embedded on the margins of the highway like airport runway lights, had not been working just east of the accident site. They were repaired Tuesday afternoon.

"We haven't been able to prove or disprove anything about the lights," Kiser said.

As the sun broke through the fog yesterday for the first time in days, just four of the 11 people who were hospitalized after the accidents remained in Charlottesville and Waynesboro hospitals. They were listed in fair to good condition.

Among those already released from hospital care were Peggy Harrah's two children, Sarah, 14, and Robbie, 8, and her mother-in-law, Pat Harrah, who were riding with her. The family had been on their way to Virginia Beach for a spring-break vacation.

"They said the fog was like nothing they had ever seen before," Parker said.