On the night shift of June 8, 2011, Jason Chenier and Jordan Fram were working at an ore pass on the 3,000-ft level of the Stobie mine. They were in the process of transferring muck from above the level to below the level through a transfer gate. They were operating the gate using a remote control pendant.

Although there was a protected area for workers at that location, to view the movement of muck and use the pendant, the two workers had to position themselves such that they were in front of and fully exposed to the transfer gate. A sudden and uncontrolled release of muck, sand and water erupted through the transfer gate, burying one worker and hitting the other.

An Ontario Ministry of Labor investigation found that there had been a hang-up of wet muck in the ore pass. The wet muck was a result of Vale not dealing with water issues in the mine.