Multiple spectators and players were sickened by an apparent carbon monoxide leak at a Saturday night hockey game in Cody.

Following the event at the Riley Arena, about 60 people sought medical attention at Cody Regional Health’s emergency department. That included the players from the Yellowstone Quake and Butte Irish junior hockey teams, who were all evaluated.

Cody Fire Chief H.R. Coe said carbon monoxide — an odorless and colorless toxic gas — affects everyone differently, but that the most common symptoms experienced on Saturday were headaches and nausea.

In a Sunday morning statement, Riley Arena General Manager Ed Bednarz thanked first responders for assisting those “who may have been impacted” by the incident and apologized “for the concern and disruption this incident may have caused.”

Though carbon monoxide can be deadly when inhaled in large enough quantities, Coe said the gas was at elevated, but nonlethal levels when his department arrived.

At the levels he saw, “it was gonna do what it did: give people a headache, make people nauseous, try and make them pretty lethargic the next day until they can get all that crap out of their system,” Coe said.

Citing respect for patient privacy, Cody Regional Health declined to say what treatment it provided, including whether any individuals were hospitalized or transferred to other facilities. Coe said some hockey players were transported to the Cody hospital by ambulance, but he said that was as a precaution.

“To my knowledge, they checked everybody [and] released everybody,” he said.

Cody Regional Health officials praised the way that their staff handled the sudden influx of patients on Saturday night.

“We are proud of how our team came together during an unexpected situation, demonstrating their training, preparedness, and commitment to caring for our community,” said Ashley Trudo, a spokeswoman for the organization. She added that, “Our thoughts remain with everyone affected by this incident, and we extend our sincere appreciation to the first responders, healthcare professionals, and community partners who helped during the response.”

Cause unclear

The apparent poisoning was only discovered after Saturday’s game had ended; everyone but the facility’s manager had evacuated when the fire department arrived.

Cody police and firefighters swept the building to ensure no one else was inside, opened all the garage doors to ventilate the building and turned off the natural gas, Coe said.

The firefighters looked for the source of the carbon monoxide, but in a building that size, “it’s fairly impossible for us to narrow down exactly where it was coming from,” Coe said. “So we just made the decision to close the building.”

He feels pretty sure that some kind of malfunction within the heating system caused the issue, but at this point, the exact cause remains under investigation. 

Coe added that it’s the first time in the arena’s roughly 20-year history that it’s had this kind of issue.

“The Riley Arena is a perfectly safe place to go watch hockey and for people to visit and be at,” the chief said, adding that, “This stuff happens.”

The fire department recommended that the Riley Arena bring in an HVAC contractor and personnel from natural gas supplier Black Hills Energy to help find the source of the carbon monoxide.

In his Sunday statement, manager Bednarz said the arena is “taking this matter seriously and working with the appropriate professionals to identify the source of the issue and ensure all necessary repairs and corrective measures are completed.”

“Normal operations will resume once the issue has been fully rectified and the facility has been confirmed safe for occupancy,” he wrote.

Park County Fire Marshal Sam Wilde said Monday that he was working to develop a plan for what the arena will need in place to reopen.

“I’m sure as we kind of get more information as it unfolds, …. hopefully we’ll have a better understanding of what happened,” Wilde said Monday, “but it’s still pretty early right now.”

Though attached to the City of Cody’s recreation center, the Victor J Riley Arena and Community Events Center is owned and operated separately, by the private, nonprofit Park County Arena Board.