A 23-year-old woman was killed Saturday night after falling through an open door on a party bus in downtown Vancouver, an incident that has raised new questions about party bus safety.

Around 24 people were celebrating a birthday party inside the bus, which was turning south on Burrard Street from West Hastings Street, at around 9:30pm.

Police say she was struck by the vehicle as it continued to turn. Passengers alerted the driver, who stopped the bus. The woman was pronounced dead at the scene by paramedics.

“I was devastated. Absolutely devastated. Took me right back to when Shannon had died,” said Julie Raymond, whose daughter Shannon died in 2008 after consuming alcohol and ecstasy on a party bus. “My heart goes out to that family.”

Police didn’t answer questions about the incident, and the name of the young woman hasn’t yet been released.

The bus involved belonged to Silver Lady Limousine Services. It’s described as a 20 or 30 passenger Ford F-series bus, with a separated cab.

The door to the rear, perimeter-seating area opens on the passenger side, the opposite direction that the bus was turning.

Silver Lady Limousine Services has been operating since 1989, documents say. In April, it was given special authorization to operate 11 party buses.

But no evidence of the company could be found at the three listed addresses of Silver Lady in Burnaby: one address was empty, another address was a post office box, and another address was a lawyer.

Late Sunday, the company issued an e-mailed statement.

“We wish to express our deepest sympathies to the loved ones of the young woman who passed away in an accident involving one of our limousines,” wrote Douglas LeMoine, the president and owner of the company, in an emailed statement.

“Silver Lady Limousine Service Ltd. Is committed to working with authorities in their ongoing investigation to determine the facts and to find out what happened,” LeMoine wrote.

Last February, the provincial government reclassified party buses to require registration with the vehicle-for-hire watchdog, the Passenger Transportation Board. This opened up operators to stiff fines if there is any drinking on board.

That was in response to the deaths of Shannon Raymond, as well as 16-year-old Ernest Azoadam, who collapsed while dancing aboard a party bus, and 17-year-old Mackenzie Gortva, who was attacked and left unconscious at an Abbotsford Truck stop after a party bus pit stop.

Consuming alcohol isn’t allowed in a vehicle in B.C., but many riders choose party buses because they want to drink. Police said they are investigating whether alcohol was involved in Saturday’s accident.

Danielle Raymond, Shannon’s sister, says she’s happy about the increased regulations, but said they don’t go far enough.

One thing that may have made a difference is requiring the party buses to have chaperones, as a bar has bouncers: sober people who are able to mind drunk passengers.

“The driver can’t drive the vehicle safely while being worried about 25 people partying,” said Julie Raymond.

NDP MLA George Heyman introduced a private member’s bill that would require chaperones, waivers, and have the driver cut short the trip if there were any violations, but the bill did not become law.