An ice rink in Gunnison, Colo., remains closed after carbon monoxide poisoning sent dozens of people to the hospital over the weekend, while another rink, in Exeter, N.H., recently reopened after a carbon monoxide scare.

More than 80 people at a youth hockey tournament at Jorgenson Park Ice Rink in Gunnison were treated for varying degrees of carbon monoxide poisoning Sunday. Gunnison Fire Marshal Dennis Spritzer told local television station KMGH that officials were looking at a possible mechanical failure in the air exchange system as the potential cause. "There may have been a problem with a damper," Spritzer said Monday. "We're still trying to isolate the cause."

The news station's website provides a harrowing account of one team's reaction to the gas:

"As soon as you walked in, you got a headache," said Susie Streeter, team manager of the Colorado Junior Eagles. Her team arrived at the rink Saturday night. The girls played a game Sunday at 9:30 a.m. They had a second game at 12:30 p.m.

"We could kind of smell gas around the rink, especially in the locker room, the whole time we were there," Streeter said. "We asked a couple people, and they said that was normal."

Streeter said, during a break between the second and third periods of the afternoon game, some of the players laid down on the ice. "I could see that something was wrong, so I went over to the bench and several of them said they were going to throw up," Streeter said. "I thought they were dehydrated. I gave them Gatorade."

"The coach kept asking the referee what was going on," Streeter said. "The referee actually told the girls, the gas is good for your brain."

"None of us felt very good," said Lauren Johnson, one of the players. "After the game, I went into the locker room and, like, blacked out."

A total of 61 victims were treated at a local hospital, fire officials said, and two of them - including Johnson of the Junior Eagles - were airlifted to a Denver hospital and treated in a hyperbaric chamber to restore oxygen levels and reduce carbon monoxide as quickly as possible. Both patients were expected to recover. Other victims also sought their own treatment.

A week earlier, The Rinks at Exeter canceled events when three people reportedly suffered symptoms of carbon monoxide poisoning after attending a high school game on Jan. 29. Exeter Fire Chief Brian Comeau told The Union Leader that a carbon monoxide buildup was caused by a mechanical failure inside the building's heating and ventilation system, The air-handling unit that removes fumes malfunctioned, creating high levels of carbon monoxide throughout the facility, which houses twin ice rinks. Comeau didn't know when the failure occurred, but said he didn't think it had been broken "for very long."

The rink, which reopened last week, has a carbon monoxide monitoring mechanism attached to the heating and ventilation system, but it wasn't working because of the malfunction, Comeau said, and a standalone carbon monoxide alarm separate from the heating and ventilation system is not required, he added.

Likewise, the Jorgenson Park Ice Rink in Colorado is not required by law to have a carbon monoxide detector. But Spritzer said that detectors will now be installed at the rink and "tied in to the fire alarm system." The facility remains closed until the cause of the leak has been determined and the problem is fixed.