03/08/2013 12:25 EST | Updated 05/08/2013 05:12 EDT

February Federated Co-op refinery fire in Regina caused by vent failure

REGINA - Investigators say a fire last month that damaged buildings and equipment at the Federated Co-op Refinery in Regina was caused by a mechanical failure.

Fire department officials say a carbon steel vent plug failed because of a chemical reaction.

This led to extreme pressure and high temperatures which caused the fire in a coker unit pump house.

No one was injured in the blaze, which was the third significant fire at the facility in 18 months.

In October 2011, corrosion in a pipe triggered a fireball that sent seven contract workers to hospital and forced 1,400 workers from the facility.

Last May, a much smaller fire occurred when an overheated crude oil pump ignited. (CJME)