Ten women — some of them in their 90s — escaped unharmed from a limousine that began smoking and caught fire in Northern California a little more than a month after five nurses were killed while trapped inside a burning limousine on a nearby bridge.

The women were celebrating one of their 90th birthdays and were in the vehicle outside the birthday woman’s home — where they had gathered shortly after 11 a.m.— when white smoke began coming out of the partition between the driver’s compartment and the passenger compartment, Mary Chapman, one of the passengers, said Monday.

The limousine was idling, but the doors were open. Chapman, 63, said she got out and the other women — some of whom relied on walkers and canes— followed with help from one another and a caregiver.

“I think that’s what saved us,” she said. “The doors were not closed, so they weren’t locked.”

Flames erupted about 15 minutes later, she said, although the women were out by then and had moved into the home. Television news footage showed the limo’s passenger and driver’s compartments completely gutted.

The limo fire on the San Mateo-Hayward Bridge over San Francisco Bay last month spread rapidly, engulfing the luxury car in just a few fleeting moments.

The five women who died were found pressed up against the 3-foot by 1 1/2-foot partition, apparently because smoke and fire kept them from the rear exits of the extended passenger compartment.

Four women and the driver managed to escape. The women were celebrating the wedding of a newlywed friend.

The California Highway Patrol has not concluded its investigation of the May 4 fire.

Industry experts say the stretch limousine industry is poorly regulated because regulatory agencies lack funds to investigate the many small businesses that modify limousines.

U.S. Department of Transportation data shows five people died in three separate stretch limo accidents in 2010, and 21 people died in another three accidents in 2011.

The 2008 Lincoln Town Car that burned Sunday was well-maintained and had 80,000 miles, said Claudius Oliveira, owner of TownCar SF, which operates the limo and two others in the San Francisco Bay area.

He said faulty wiring was responsible for the fire and blamed the manufacturer.

Typically, stretch limos are either modified by a company that customizes and stretches the vehicle or by whoever bought the limousine directly from the car maker. The manufacturer modified the car in this case, Oliveira said.

Walnut Creek police Lt. Jay Hill said the vehicle was licensed to carry only eight people. But he said there was no indication of any criminal wrongdoing.

Hill declined to provide the driver’s name.

TownCar SF is currently authorized to operate, said Terrie Prosper, a spokeswoman for the California Public Utilities Commission, which regulates limos. The company was suspended in August 2011 for not having worker’s compensation insurance on file and once in early 2011 for not having liability insurance on file, but other than that, it has not been penalized by the agency.

The limousine was listed with the CPUC as seating eight passengers including the driver, according to Prosper, which meant it did not have to be inspected by the California Highway Patrol, which inspects vehicles seating more than 10 including the driver.

Prosper said in an email that with regard to Sunday’s limousine fire, the agency is “looking into the matter and will obtain the official number of passengers.” She said if the company misrepresented the limousine’s seating capacity to the agency, it could be fined $7,500 for per day of violation.