An unexpected thunderstorm drove a lightning bolt into the chimney of a Thunder Bay business this afternoon.

The incident happened at Lakehead Cleaners on Memorial Avenue.

The blast blew out pieces of the brick chimney and sent debris tumbling to the ground.

Wade Clarke was working at Payless Automotive next door when the lightning hit.

"We heard a huge bang, sounded like a plane hit the building, and a huge lightning bolt flew over the shop out towards Fort William Road towards the Wholesale Club."

Nobody was reported hurt in the incident.

Bruce Carruthers, general manager of Lakehead Cleaners, said the chimney is not in use. 

There was no thunderstorm activiy in the Thunder Bay weather outlook this afternoon.

Ronald Lee is a severe weather forecaster with Environment Canada. He said the storm dumped almost 20 mm of rain in about 20 minutes and packed winds of 50 km/h, but did not meet the criteria for any severe weather watches or warnings.

"A line of thunderstorms did develop and move by .... it really just came up and moved to the south of you and into the lake."

Lee said "unstable air" in the Thunder Bay area created the right climate for the storm to form.