Hot-air balloon operators are shocked by the crash of a balloon that killed a mother and daughter and injured 11 others in the Vancouver suburb of Surrey on Friday night.

"What we've seen on the news, obviously, those pictures are not very nice,'' said hot-air balloon pilot Graham Rowlinson, referring to video of the flame-engulfed balloon plummeting to the ground in a trailer park.

"They've been very shocking to everybody in the industry.''

Rowlinson told The Canadian Press that without knowing the exact circumstances surrounding the tragedy, "it's very difficult for us to understand why this may have occurred."

But he said the industry has a very good safety record, estimating there have been about five hot-air balloon related deaths in 40 years in Canada.

Rowlinson has operated Cambridge, Ontario's Skyward Balloons and has 30 years experience as a pilot, flying fixed-wing aircraft and hot-air balloons.

Pending investigations into the cause of the crash, Surrey, B.C.'s Fantasy Balloons has suspended its operations.

Transportation Safety Board investigators plan to interview Stephen Pennock, the pilot of the hot air balloon. Pennock suffered burns to his face and arm, and will likely speak with investigators Tuesday.

"The intent was to meet today, but he was not feeling well enough," said Transportation Safety Board spokesperson Bill Yearwood.

He has not set a timeframe for how long the investigation will take and indicated that it was too early to determine a cause of the fatal fire.

Investigators are examining the remains of the aircraft and its four large propane tanks, to determine how the balloon caught on fire. Witnesses have offered possible clues, saying they heard a popping sound.

"We know now from witness information that there were some abnormal noises, referred to as pops and hisses," Yearwood told CTV British Columbia.

The flames suddenly went sideways and the pilot told passengers to jump out.

But as the weight inside the basket decreased, the balloon quickly drifted into the air, along with Knackstedt and her daughter. Flames then burned through the tether keeping it attacked to the ground.

The family had been celebrating the mother's 50th birthday.

Some witnesses suggested the pilot may have left the basket first, which would have been company policy, said a spokesperson for Fantasy Balloon Charters.

John Kageorge said pilots have a better chance of helping passengers escape from outside the basket.

"The best way he could help those people was not being in the centre of a ball of fire surrounded by four 100-pound canisters of propane," he told CTV's Canada AM.

"Just like jellybeans in a jar, you can't get them out from the inside, you have to be on the outside to pull them out."

However, he indicated that any significant findings in the investigation would be relayed to Transport Canada, which regulates the hot-air balloon industry.

This is the second hot-air ballooning accident in Canada this month. Two people were injured when a balloon in Manitoba caught fire on Aug. 11.

Survivor story

A woman who survived a horrific hot-air balloon crash in B.C. said she had just seconds to decide whether to risk a five-story fall, or remain inside a burning basket as it rose into the air.

Diane Rutledge jumped, shattering the bones in her feet as she hit the ground in the Vancouver suburb of Surrey.

Ten other passengers also survived, but two never escaped: Shannon Knackstedt and her daughter Gemma, of Langley, B.C.

Rutledge said that on the ground, Knackstedt's husband began frantically searching for his family.

"I'm laying on the ground and looking at the sky, but he's looking around for his wife and daughter. He was saying, 'Did anybody see? Did anybody see my wife and my daughter?'" Rutledge told reporters from her hospital bed.

"He was looking at the balloon, because he knew there were two people in the balloon. He was shaking people, shaking police and almost running in circles. But he never found them."

With a report from CTV British Columbia and files from The Associated Press