The Ontario Fire Marshal's office is investigating Wednesday's early morning house fire in downtown Sarnia.
Sarnia Fire Rescue responded to a heavily involved structure fire on Brock Street North near Lochiel Street at around 2:30 a.m.
Fire Public Education Officer Mike Otis said damage to the unoccupied two-storey home is extensive, and it is expected to be a complete loss.
He said the cause of the blaze is still under investigation.
Otis said neighbours did report hearing an explosion, however, they have not determined yet whether it was the primary cause of the fire, or a result of the fire.
There were no injuries reported.
