All underground operations have been suspended at a mine near Sudbury, Ont., after two contractors died following a ground collapse early Tuesday morning.

Mining company First Nickel Inc. said "a fall of ground, preceded by seismic activity," is believed to have been a factor in the accident that left two drillers, 34-year-old Marc Methe and 49-year-old Norm Bissaillon, dead.

Both men were working for Taurus Drilling Services.

Rescue teams and emergency officials were dispatched to Lockerby Mine immediately after the accident. They “worked tirelessly” to reach the two men, but thedrillers were pronounced dead on scene, said First Nickel CEO and President Thomas Boehlert.

No other workers were injured.

First Nickel said it's working with Taurus Drilling to ensure that the men’s families receive support. Counselling will also be provided for workers who were on the site at the time of the accident.

"We are deeply saddened by this tragic accident that resulted in the deaths of two men and we extend our heartfelt condolences to their families, friends and colleagues," Boehlert said in a statement. "Safety is the top priority for the company and we will ensure this accident is fully investigated."

Bissaillon was described as a “dedicated” underground miner with over 20 years of experience. He was a “good man, (a) family man” who loved to talk about his children, Boehlert told reporters Tuesday.

Methe had been a Taurus driller for about four years, Boehlert said. “He was very committed and enthusiastic about the trade, always positive and meticulous in everything he did.” 

Mine Mill 598 Unifor President Anne Marie MacInnis told CTV News Channel that although the workers were not unionized, she is requesting that Unifor be part of the joint investigation into the accident.

"We want to ensure the investigation is done correctly and there's transparency," she said. 

Ontario's Ministry of Labour is investigating the accident.

The ministry's chief prevention officer called the deaths "unacceptable."

"We must find better ways of protecting people who go into mines every day to earn a living," George Gritziotis said in a statement. "No job is worth a life." 

Sudbury Mayor Marianne Matichuk said Tuesday the city has endured a "tragic accident."

"On behalf of city council and all citizens of Greater Sudbury, I offer my condolences to the families, friends and co-workers of the individuals. Our thoughts and prayers are with them during this difficult time," she said in a statement.