Fiery explosions destroyed a Zamboni and severely damaged the ice arena it served, rocking Duluth's broomball and hockey seasons.
Leaking propane from a parked Zamboni ice resurfacing machine was blamed Monday for blasts and a fire that ripped through Peterson Arena in the midst of a broomball game Sunday, causing about $850,000 in damage.
"We're seeing broomball sticks all over the place today," said Duluth Fire Chief John Strongitharm.
Broomball players and fans, who escaped serious injury, said the explosions came from a room where a Zamboni ice-resurfacing machine was stored. The doors to the room blew across the rink. Some players were knocked down and some had shards of the rink's Plexiglas blasted into their exposed skin.
Most players were at the opposite end of the arena from the explosion, Strongitharm said.
"I would think it is very fortunate that the explosion happened when the people were away from that door and they all had the sense to drop their broomball sticks and get out," Strongitharm said.
He said calm and fast thinking by the players and fans probably saved lives.
"There were an enormous amount of combustibles in the building," Strongitharm said.
The fire was so intense that the building's steel framework was bent in places, which may make the building unsalvageable, he said.
Mayor Herb Bergson said Fire Marshal Erik Simonson determined the leaking gas reached an open flame on a gas-fired hot water heater, which triggered the explosion. After the initial blast there were at least two other explosions, which Simonson believes also were caused by propane tanks stored in the arena.
Propane is the fuel generally used by resurfacing machines, although some operate on electric batteries and some use natural gas, said Walt Bruley, who has operated resurfacing machines for more than 30 years.
Bruley, also a district representative for the Minnesota Ice Arenas Managers' Association, said Zambonis are built with a number of safety valves aimed at containing any potential propane leak.
"These things don't just blow up," Bruley said. "There were many things in that room that probably could have blown up besides the machine."
Propane generally is considered a safer fuel than gasoline because it doesn't ignite as easily, it produces less harmful fumes when burned and it has an additive that gives it a distinctive smell, making leaks easily detectable. Propane is also heavier than air and generally sinks to floor or ground level where's it easily vented, Bruley said.
"If there was a leak it would have been something that could have been smelled," Bruley said. "This is a very, very rare occasion."
The loss of one of its two indoor hockey facilities is a major blow to the Duluth Amateur Hockey Association.
DAHA Executive Director Clarke Coole met with city officials Monday to discuss the fire.
"We're down a facility and this is the prime time of the season," Coole said. "This is going to impact our program enormously."
The association serves about 800 youth hockey players. Coole said youth hockey tournaments had been scheduled every weekend in the building throughout January, February and half of March.