REVELSTOKE, British Columbia — An avalanche that killed two people at an informal snowmobile rally in Canada’s Rocky Mountains may have been triggered by three daredevil sledders who apparently unleashed a deadly wall of snow on up to 200 people below, witnesses said Sunday.

The Royal Canadian Mounted Police said an even worse tragedy may have been averted because many of the snowmobilers had come equipped with avalanche recovery equipment and dug people out even before rescuers arrived at the scene.

RCMP Cpl. Dan Moskaluk told a news conference Sunday that two men are confirmed dead, not three, as reported earlier in the chaotic hours after the slide.

Moskaluk later said the search is over. He said they had searched for abandoned vehicles and canvassed area hotels, and there is nobody that they know of left unaccounted. The slide struck around 3:30 p.m. Saturday on Boulder Mountain.

Moskaluk said the avalanche was “human-triggered,” and police and the coroner’s office will investigate all aspects of the incident and the deaths.

Thirty people were injured, he said, including a person in critical condition and three others in serious condition who were taken to regional hospitals.

Despite avalanche warnings, about 200 people had gathered on the mountain for the Big Iron Shoot Out, an annual unsanctioned event known for its party atmosphere and stunt riding that has become popular among people who enjoy snowmobiling in the deep snow of back country British Columbia.

Two men who witnessed the avalanche said it hit so many people in part because a crowd had stopped at the bottom of the mountain to watch three snowmobilers perform a stunt known as high-marking — a contest to see who can race up a slope and leave the highest mark.

Steve Langevin, 38, said he thought the crowd was safe from “those crazy guys” because the snowmobilers seemed like they were miles away, but the wave of snow was so massive it easily reached them.

His friend, Pierre Beaudoin, 48, said he thought the accident could have been prevented if people hadn’t been irresponsibly high-marking in avalanche-prone conditions.

“The minute one makes it to the top, oh, the next guy, ‘I could do it,’ and then it becomes stupid. And it was stupid, they were starting to come from the side, one’s coming down and one’s going up,” he said. “Then everything started going crazy.”

Revelstoke Mayor David Raven said an avalanche warning had been in place for three weeks.

“A fresh snowfall overnight exacerbated that warning,” he told CTV Newsnet.

Moskaluk said police lacked the authority to shut off public access to sites in the area like Boulder Mountain even if avalanche warnings were in effect.

“People need to risk-assess their leisure activities,” Moskaluk said. “It appears a number of the people that were participating (in the rally) were able to self-rescue prior to emergency services arriving.”

The avalanche occurred near Revelstoke, about 185 miles west of Calgary and about 250 miles northeast of Vancouver.