Sixty-three miners headed to underground shelters during a fire at Nurtrien’s potash mine in Allan early Tuesday morning.

“There are a number shelters strategically placed underground. Anytime there’s an incident and a hazard, they are taken to those shelters,” Nutrien spokesman Will Tigley told CTV News.

“Our priority is the safety of our employees."

All 63 workers are above ground. Operations have stopped until further notice.

Emergency services teams on site were able to control fire and did not need help from the local volunteer fire department, Tigley said.

CTV News spoke to one of the workers who spent the night in a refuge station. He did not want to do an on-camera interview but did say he was working underground when he and the other workers were alerted there was a problem by “stench gas.”

The gas smells like rotten eggs and is released throughout the mine when there is an emergency.

“You smell it. You’re in high gear,” he said as he was leaving the mine shortly after 11 a.m.

The workers are supposed to go to the nearest refuge station. At that point, they seal themselves in and make sure everyone is accounted for.

“We get tons of training on this,” he said. “Everybody knows their role once they get there.”

Then they wait.

The worker says many of the people had their phones and were playing games. Some slept and watched movies. But at least one person needs to stay awake in case rescuers arrive.

“You can’t have someone asking if people are alright, and not have someone awake to answer.”

The cause of the fire is under investigation.