The limo that caught fire, killing five women, was carrying one more passenger than allowed by state regulations, the California Highway Patrol said Monday.
Nine women were inside the 1999 Lincoln Town Car stretch limo despite rules allowing the car to transport only eight passengers.
The limo burst into flames westbound on the San Mateo Bridge near Foster City, Calif., killing five women, including the recent bride.
Cmdr. Mike Maskarich of the California Highway Patrol told a news conference that investigators do not know whether carrying one extra person contributed to the cause of the fire or made it more difficult for the women to escape.
The limo's driver Orville Brown told police that the four surviving women managed to escape the limo by squeezing through a 3-foot-by-1 1/2-foot partition between the cab and the rear.
San Mateo County Coroner Robert Foucrault told the Los Angeles Times that the women who died inside the limo were "basically on top of one another, kind of huddled" below the window, indicating they were trying to escape.
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Foster City fire officials said they did not know yet whether the stretch limo had a fire extinguisher on board of if its two rear doors could be opened from the inside.
All of the women were registered nurses out celebrating a bachelorette party for the recent newlywed, who was planning to travel to her native Philippines for another wedding ceremony in front of her family.