Production Manager Ken Berg pulls a cord to activate a set of air-lock doors as he travels through a Mosaic Co. potash mine in Colonsay, Saskatchewan, Canada, on Tuesday, March 22, 2011. Photographer: Daniel Acker
The headlights of a Caterpillar underground mining loader shine in an otherwise pitch black Mosaic Co. potash mine in Colonsay, Saskatchewan, Canada, on Tuesday, March 22, 2011. Photographer: Daniel Acker
A table sits in a work area at the Mosaic Co. potash mine in Colonsay, Saskatchewan, Canada, on Tuesday, March 22, 2011. Photographer: Daniel Acker