Sarnia police say Vidal Street South will fully reopen Wednesday afternoon after a tower collapsed inside the Sarnia Imperial Oil site Tuesday evening.

The tower was scheduled for maintenance and was not in service when it fell.

The company issued a Code 6 and it's working with local authorities. Imperial emergency responders sprayed water on the structure as a precaution.

According to Imperial Oil, through their Facebook Page, all employees have been accounted for since the tower's collapse.

"Community members will notice high flaring from the site," the company said, adding that a full investigation into the cause of the collapse will happen.

Imperial Oil has also initiated air monitoring, and readings have shown zero.

Police say the company will continue to monitor and assess the situation.

Reason for collapse

At this point, it's not clear why the tower had collapsed, said Sarnia Mayor Mike Bradley, but he said "it's highly unusual" for something like this to happen.

Mayor Mike Bradley says it's not clear as to why the tower collapsed Tuesday night. (Colin Côté-Paulette/Radio-Canada)

Bradley has been told that the Ministry of Labour and Ministry of Environment have been contacted about the collapse.

He's hoping to find out why the tower went down, because a lot of plants and structures in Sarnia are of a similar age as Imperial Oil.

"Because any time you have a failure of that nature, something physically collapses, there's issues there that needs to be addressed," said Bradley. "If one plant went down, could another one go down?"

He will be meeting with officials later on Wednesday to discuss the situation.