VALLEY CENTER, Calif., Oct. 28— A black, burned patch of asphalt marks the spot where Ashleigh Roach died in her car in a whipping storm of fire, less than 200 feet from the front gate of her home.

Ashleigh, a 16-year-old who had been dancing Irish jigs since she was 3; her sister, Alyson, 20; their brother, Jason, 22; and a young marine they had befriended had been trying to escape the flames that descended with fury on the Roach family's mountainside property on Sunday, here in what were once the beautiful rolling hills of northeastern San Diego County.

Alyson and Jason were hospitalized with severe burns, as was the marine, who was identified by neighbors as Stephen Leavitt. The Roach home was leveled by the flames, as were most of the houses surrounding it.

''I hadn't seen anything that bad since Vietnam,'' said Aaron Hayes, a neighbor who did two Navy tours in Southeast Asia, as he described the fire that engulfed the neighborhood on Station Road here.

Ashleigh Roach was one of at least 16 people who have died in the Southern California fires of the last few days. Two more are believed to have been killed in Baja California, Mexico.

Glenn Wagner, the San Diego County medical examiner, said Tuesday morning that of the 12 known deaths in his jurisdiction, 10 had occurred in vehicles, as people tried to race away from the flames.

Some victims were so badly burned that they were being identified by the metal tags on the collars of the dogs lying dead near them. One was believed to be Stephen Shacklett, who was last seen alive as he gathered his four Irish wolfhounds into a recreational vehicle just ahead of the flames advancing on his neighborhood in the hills south of the San Vicente Reservoir. He was later found dead inside the incinerated vehicle.

Three of his neighbors, James Shohara, his wife, Solange, and their son, Randy, also died in their car on Muth Valley Road, the only way out of their mountain community.

Some of those who survived such escapes were nevertheless horribly burned. At the University of California-San Diego Medical Center, 14 people were admitted for treatment of burns or smoke inhalation. Five were in critical condition on Tuesday, including Alyson Roach, with burns over 85 percent of her body. Her brother suffered burns on his face and neck and was released after treatment.

John Hyatt, a family friend, said of Ms. Roach, ''She's fighting for her life; she's struggling.''

The Roaches' path was impeded by smoke so thick that visibility was down to a few feet, said a neighbor, Ken Frederiksen, who made it out of the area about the same time.

The Roaches' Ford Mustang, apparently driven by Jason, crashed into another vehicle as they tried to leave, and could go no farther, said Mr. Frederiksen's wife, Alisa, who was in her own car and came upon Jason as he flagged her down.

''Here was this kid, he comes out of the smoke, and he was screaming that Ashleigh was still in the car,'' Mrs. Frederiksen said on Tuesday afternoon at her house, which was spared. ''We turned around and there was this big wall of flame. It comes at us like it's a tornado. I said to him, 'You can't go back, get in the car now!' ''

While Mrs. Frederiksen took Jason to the fire station less than 500 feet down the road, her mother-in-law, Mabel O'Brien, picked up the young marine, Mr. Leavitt, in her car and took him to a friend's house nearby, where he was later collected by paramedics.

The Roaches' property and those around it looked desolate on Tuesday, the ground charred, the sky a pallid gray and filled with the sting of smoke. The young Roaches' parents, John, a construction supervisor, and Lori, escaped unharmed. A couple of months ago, the family visited Ireland, their ancestral country. In San Diego, they were members of the House of Ireland. That community group was helping to organize a memorial service for Ashleigh on Thursday in Escondido, 10 miles south of here.

''They had done a really nice job with that house,'' said Mr. Hayes, their neighbor. ''They had just finished the new deck on Friday and on Saturday they had a Halloween party. Everybody was invited, even the paramedics and firemen from down the road. They brought their engines and parked them outside.''