The first of dozens of miners who had been trapped underground for more than 24 hours following an incident at a mine in northern Ontario began returning to the surface late Monday, their employer said.

An official with mining company Vale, Gord Gilpin, said in a statement that they were “relieved and delighted to see these individuals returning to surface safe and sound.”

Vale had said earlier in the day that a rescue team had reached the 39 workers, who were in several different “refuges” between 900 and 1,200 metres underground at Totten Mine, located about 40 kilometres west of Sudbury, Ont.

No one was injured, and Vale said it expected all 39 employees to return to surface in the coming hours.

The company said the workers became stuck after a scoop bucket being transported underground on Sunday detached and became hung up in the shaft, rendering normal conveyance for transporting employees unavailable.

The employees could still get out, the company said, but it meant they faced a long climb up a secondary egress ladder system with support of Vale's mine rescue team.

“There is no doubt this was and continues to be an exhausting experience. I commend them on their patience and their resolve,” Gilpin said in the statement late Monday.

“I also want to acknowledge the efforts of our mine rescue team and Totten responders who are working tirelessly to bring their colleagues to surface safely.”

The mine produces copper, nickel and precious metals and employs about 200 people.

The company said the trapped miners had access to food, water and medicine. A spokesman for the United Steelworkers said that some of the trapped miners needed insulin.

A statement from the United Steelworkers, the union which represents 30 of the 39 staff members trapped in the mine, said it was cautiously optimistic all of the workers would be safely evacuated as soon as possible.

“This is a very difficult time for these workers, their families and co-workers, and our thoughts are with them,” said Nick Larochelle, president of USW Local 6500, which represents most Totten Mine employees.

Pascal Boucher, the union's area coordinator for Sudbury and the north, said earlier Monday that the miners could still move around within their compartments in the shaft and that they rested before scaling the ladder system.

“Everyone has a different physical ability,” said Boucher, noting that each ladder is 20 feet long with a staging area at every break. “We have older senior employees and much younger employees, who could probably climb it faster.”

Boucher noted that the miners had been able to place phone calls out of the mine shaft, both to communicate with rescuers and to call loved ones.

He added that he overheard one call from the miners wondering when their sandwiches would arrive.

Ontario Premier Doug Ford said Monday afternoon that his thoughts were with the miners.

“We understand this rescue will take some time and are very relieved to hear the miners are currently uninjured,” he said on Twitter.

Totten Mine opened in 2014, in Worthington, Ont. -- the first mine to open in the area in 40 years, according to the company's website.

Kalem McSween, a spokesman for the province's Ministry of Labour, Training and Skills Development, said in an email that an inspection team will investigate the incident once the rescue operation is finished.