The three people believed to have been killed by an ammonia leak at a Fernie, B.C. hockey arena Tuesday were workers doing routine maintenance, according to the mayor.

The deceased have not been publicly identified, but Mayor Mary Giuliano said two of them were locals who worked for the city.

"I would like to extend our deepest condolences to the families involved in this tragic event," she said at a news conference Wednesday.

The third victim was a contract employee from Calgary who worked for CIMCO Refrigeration.

Some of the properties surrounding Fernie Memorial Arena remain under an evacuation order, including the Fernie Curling Rink, 7-Eleven, and Trinity Lodge retirement home, but Giuliano said residents have been going out of their way to support evacuees.

"Fernie is a tight-knit community and I know we will pull together and support one another as we have in the past," she said.

"The city is arranging for support for the families and our workers to help manage the grief and stress we are all feeling."

Hotels were provided for about 25 displaced residents, according to officials.

A local state of emergency that was declared in the aftermath of the ammonia leak also remains in effect as crews work to address the potential "threat to property and life."

Officials said the state of emergency will last seven days unless the city or minister decides it can be cancelled sooner. Those looking for more information on the status of the evacuation and those who may need assistance as a result are asked to visit the City of Fernie's website or call the information line at 1-855-346-2188.

A hazmat team from CIMCO Refrigeration was brought in to help contain the leak, and staff from B.C.'s Ministry of Environment was dispatched to assist with monitoring.

Fernie Fire Chief Ted Ruiter said the tragedy has been challenging for the community to process.

"Yesterday was an extremely difficult day for us here in Fernie," Ruiter said.

Fire crews arrived at the arena Tuesday afternoon to find a bystander performing CPR on one of the victims. They found the two others inside shortly after, but were forced to leave the premises for their own safety.

Ruiter said it still was too dangerous to go back inside by midday Wednesday.

The leak has been identified as anhydrous ammonia, a chemical used in farming, cleaning products and refrigeration systems.

"It's a product that is used commonly in arenas for refrigeration," Ruiter said. "We are doing a perimeter check of levels in the air."

The RCMP is leading the investigation into what happened until it can determine whether anything criminal contributed to the leak. Mounties are working alongside investigators from WorkSafeBC and the BC Coroners Service.

With files from The Canadian Press and CTV Calgary's Ina Sidhu