Bich Ngo was declared dead at Irvine Regional Medical Center after the roughly 5:30 a.m. accident Saturday, and an autopsy showed he bled to death, said Rod Thomas, an Orange County deputy coroner. Investigators found no evidence that Ngo had a medical emergency before the crash, he said.

"The male driver and passenger were in the parking lot upper level when their '85 Nissan Maxima unexpectedly accelerated and struck one of the structure's columns," said Orange County sheriff's Lt. Ted Boyne. "The driver, who was not wearing a seatbelt, sustained fatal injuries.

"We're exploring the possibility of pedal confusion, but we don't know yet," he said.

Ngo and his passenger, a 72-year-old woman whose name was withheld, are associated with the Buddhist temple in Rosemead, police told the Orange County Register. Boyne said the woman was riding in the back when the crash occurred.