09/26/2012 07:25 EDT | Updated 11/26/2012 05:12 EST

Potash mine readies to resume operations after fire

Mining activities are expected to resume soon at the potash mine near Rocanville, Sask., where workers had to spend several hours in safe rooms following a fire Tuesday.

Officials from PotashCorp said crews had completed tests of air quality and an internal review had begun to learn more about what led to the fire.

The mine was shut down after the fire stranded 20 workers in underground safe rooms.

The fire was noticed around 2 a.m. CST Tuesday morning and was extinguished a few hours later.

It then took several more hours to cool the site and ventilate the underground space before the workers could return to the surface.

Everyone was finally out, safe and sound, around 8 p.m.

Meanwhile, a national union that represents mine workers, the Communications, Energy and Paperworkers Union of Canada, issued a news release Wednesday calling on the government of Saskatchewan to launch an inquiry into mining industry safety.

According to CEP's president, Dave Coles, there have been three fatalities at potash mines in Saskatchewan in the last two years.

Coles also touched on another underground fire, in 2006, where 72 union members were trapped for a time but ultimately returned safely to the surface.

"An inquiry to see if proper safety procedures and protocols are being followed is definitely in order," Coles said. "One accident is one too many."