A hot air balloon's basket is engulfed in flames shortly after takeoff when it was about 25 feet off the ground Friday in Surrey, British Columbia.

Vancouver, British Columbia ? A hot air balloon burst into flames over western Canada, burning a woman and her adult daughter to death while their families looked on, officials said Saturday. Other passengers leaped to the ground, some with their clothes in flames, witnesses said.

Eleven passengers were seriously injured when the balloon crashed Friday evening in a recreational vehicle park near the U.S border in Surrey, British Columbia, a suburb of Vancouver. There were 12 passengers and a pilot on board, police and witnesses said.

John Kageorge, who works for Fantasy Balloon Charters, said the fire started as the ballon was about to launch. Kageorge said three passangers did not get out of the basket before it became airborne.

“One person jumped from an unsafe distance, two stories in the air or more,” said Kageorge. The mother and daughter did not jump, he said, although two of their family members made it out of the basket.

Royal Canadian Mounted Police Sgt. Roger Morrow confirmed the deaths and said relatives of the two passengers killed witnessed the fire.

“It’s just tragic. They watched it unfold before their eyes,” Morrow said of the family. “The fatalities suffered from burns.”

The balloon caught fire as it prepared to launch, said Bill Yearwood, an investigator with the Transportation Safety Board of Canada.

“The crew loaded 12 passengers and was preparing to launch when a fire erupted. The pilot asked the passengers to get out of the basket,” he said. “The balloon was tethered at the time, but then broke and came loose,” he added.

After most of the passengers escaped, the balloon exploded in a fireball and shot up into the air. Shortly after, the burning balloon plunged to ground in the RV park, leaving a tail of thick black smoke in its wake.

“I can’t tell you what exactly happened when the balloon was loosened from the tether,” Yearwood said. “We will be talking to attending crew members and the pilot to find out.”

He said the pilot was in stable condition.

“The thing went up about 400 feet in the air at which point it melted enough of the balloon – it collapsed,” said Don Randall, a resident of the trailer park who took pictures of the scene. “The basket was basically a fireball. It just dropped like a stone,” he added.

“I’m just thinking, ‘Oh geez, I hope there’s nobody in that thing. It’s basically a burning death up there,”‘ he said.

The cause of the accident was not immediately known. Weather conditions were clear at the time of the sunset flight.