A large section of the roof of the Rostraver Ice Garden, near Pittsburgh, collapsed Sunday afternoon during a children's hockey tournament involving teams from Canada and the U.S. (John Heller/Associated Press)

Emergency officials said everyone has been accounted for and no one was injured Sunday after a large section of roof collapsed at a suburban Pittsburgh ice rink.

The collapse at the 5,000-seat rink in Rostraver, Pa., came during a children's hockey tournament involving teams from the U.S. and Canada.

There was confusion after the collapse, with people unaccounted for, and authorities carefully searched the building using cadaver dogs and infrared cameras before declaring that everyone was safe.

Rostraver Central Fire Department assistant chief Justin Shawley said no one was found in the damaged building.

Mike Stangroom, director of operations for Rostraver West Newton Emergency Services, said he doesn't know how many people were in the Rostraver Ice Garden, about 50 kilometres southeast of Pittsburgh, when a 30-by-60-metre section of it collapsed about 3:30 p.m. ET Sunday.

A children's team from Ajax, Ont., was competing in the tournament. Sherri Desroches, vice-president of Ajax Minor Hockey, identified it as the Ajax Knights Tyke White team.

"These little boys are seven and eight years old. Tykes are pretty tiny," Desroches said.

Team from Ajax, Ont., unhurt

She said she received a text message Sunday evening from the coach, Gary Maclean, advising her that all 18 children were safe and unhurt and were on their way home.

A team of six- to eight-year-olds from Erie, Pa., was in the locker room celebrating a victory when they were told to get out of the rink, according to the website GoErie.com.

Parent Mark Natemeier and coach Chris Shearer said the roof made popping noises and sounds like sticks breaking before it came down, giving people time to get out of the rink.

Erie Hockey Association president Jeff Cross said everyone from his team was accounted for and escaped injury.

Kids had just left ice

Coach Maclean said it was fortunate that his Ajax team missed its scoring chances late in the game, since a goal likely would have meant overtime.

"The last couple of minutes we had a lot of chances to tie the game, and if we had tied the game the kids likely would've been on the ice when the roof caved in," Maclean said.

He said the team had just left the ice for the dressing room when a parent rushed in, screaming that the roof was caving in.

The children had only minutes to leave the building, as they charged for the doors while the old structure crumbled behind them.

"It sounded like the pressure crack on a lake, but it was very, very loud, and as the roof caved in it displaced a lot of air," Maclean said.

"With my son in my hand, the pressure of the wind basically lifted me and pushed me out the door, that was the force of it," he said.

Maclean said the children were crying, and clinging to parents who were relieved once they realized everyone escaped unharmed.

"A lot of people are really shaken up, a lot of the kids are shaken up. My own son has been traumatized by the whole thing," he said.

The cause of the collapse hasn't been determined, but the area was reported to have received a heavy snowfall.

With files from The Associated Press and The Canadian Press