Twenty miners are free after they spent a night and day trapped underground, after a fire broke out at a PotashCorp mine in Saskatchewan.

The blaze erupted at 2 a.m. Tuesday when a wooden cable spool caught fire at the Rocanville mine, about 245 kilometres east of Regina.

Managers had ordered the 20 miners into four “refugee stations” and were in contact with them throughout the ordeal. It took 10 hours to extinguish the fire, and another seven for crews to determine the miners could leave safely.

Darwyn Wirth, one of the 20 miners who had been trapped, knew exactly what he wanted to do Tuesday night as he finally made it above ground.

"I think I'm going to go and have a cold beer," he told reporters.

Twenty-nine miners were originally underground, but a fire rescue crew was able to get nine of the miners safely to the surface.

A second fire rescue crew then went into the mine to battle the blaze and attempt to rescue the remaining workers.

Terry Daniel, PotashCorp's mill operations superintendent, said it’s still unclear why the fire was sparked.

“What ignited it, the course of the investigation will reveal,” he said. “I can’t even being to speculate at this point.”

The Rocanville mine is about one kilometre below the ground and its tunnels spread out horizontally for 16 kilometres.

In early 2006, 72 miners were rescued from Mosaic’s potash mine in Esterhazy, Sask., after a fire broke out below.

The rescue took 30 hours and none of the miners were injured.

With files from The Canadian Press