PotashCorp said 54 workers remain underground in the east wing of the mine. The company said everyone is safe and it expects to get those employees to the surface later this afternoon.
Power and phone communication was knocked out at the mine, but PotashCorp said mine safety workers and oxygen masks were able to reach the trapped workers.
A PotashCorp spokesperson said the fire broke out in a water truck deep underground around 4 p.m. CST Wednesday. That forced almost 100 workers to make their way to refuge stations throughout the mine.
Whenever there is a fire, strict safety protocols dictate that miners must make their way to refuge stations underground, to ensure they are safe from the flames and have fresh air.
There are no reports of injuries from Wednesday's incident.
The smoke, however, is lingering in some parts of the potash mine because the fire knocked out a couple of the fans used for circulating air underground, so the company hasn't yet sounded the all-clear.
According to a spokesperson, the mine is closed as company officials investigate.
They hope to return to normal mining operations on Friday.