An industrial business near Hensall has been destroyed after a massive fire.

Fire officials say the damage could be upwards of $2.5 million.

The fire started around 5 p.m. at Glavin Coating and Finishing.

A secretary, getting ready to leave for the day, saw smoke and called 911.

Seven fire departments and more than 60 firefighters were called to the fire.

Fire officials say several nearby homes were evacuated due to potentially toxic smoke.

The Ontario Fire Marshall has been called in to investigate due to the extent of the damage.

The cause of the fire is unknown.