Burned Boy in Critical Condition : Fire: A Las Vegas hospital is treating the survivor of a Downey garage blaze that killed three. Officials are seeking a cause for the fire.

A 13-year-old boy, the only survivor of a garage fire here that killed three people, remained in critical condition Wednesday at a Las Vegas hospital.

Dale Pugh, a spokesman for University Medical Center of Southern Nevada, said Lucas Frausto, 13, of Downey, is being treated for second- and third-degree burns to 50% of his body.

Rafael Frausto, 20, Victoriano Frausto, 17, and Jaime Herrera, 18, all of Downey, were severely burned in the garage fire at a vacant house on the 9400 block of Pico Vista Road. They died from their injuries within hours of the blaze, Fire Capt. Dennis Lockhard said.

Lucas Frausto was transported to the Las Vegas hospital because local burn units had no other beds available, a Rio Hondo Hospital spokeswoman said.

Police and fire investigators said Wednesday that they are trying to piece together how the fire started and the victims’ relationship; three are thought to be brothers.

The fire started shortly before 2 p.m. Sunday, after the youths removed the gas tank from a car, Lockhard said. Gasoline fumes were ignited by a water heater in the closed garage.

“We don’t know why they were fooling with the gas tank,” Police Capt. Bob Williams said. “Because of the gravity of the incident . . . we have to determine whether there were any criminal acts involved.”

Police have been unable to interview Lucas Frausto because of his injuries, Williams said.

When firefighters arrived, they found Rafael Frausto in front of the house. Paramedics took him to Downey Community Hospital, where he died Monday morning. He suffered burns to 95% of his body, Lockhard said.

The other three victims apparently drove themselves to Rio Hondo Hospital in Downey, Lockhard said. Victoriano Frausto was burned on 95% of his body, while Herrera suffered burns to 75% of his body. They were transported to hospitals in Orange and San Diego, where they died from their injuries.

Investigators are trying to find out why the four were working in the garage of the vacant house, which was being sold. The fire caused about $5,000 in damage to the house, Lockhard said.

“We have not been able to establish a family relationship between the owner and victims,” Lockhard said. “What reason did they have to be in a person’s house? We’re they renting? We don’t know.”