Authorities are getting closer to finding out what caused a massive explosion at the Regina refinery back in October.

Albert Headrick with the Regina fire department says they have released the scene back to the Consumers' Co-operative Refineries on Dec. 5.

But he stresses they still don't have a final report on exactly what happened.

“At this point we are waiting on information in relation to root cause and analysis that was conducted by an outside firm that specializes in these techniques,” said Headrick.

Those techniques are part of a comprehensive review of systems and processes that have been in place at the refinery as well as samples of material.

The information is expected to come back sometime in 2012.

Edited by News Talk Radio's Chris Morin.