No injuries are reported in an early morning fire Tuesday.
Sarnia Fire and Rescue responded to a structure fire on Davis Street at around 4:30 a.m.
Chief Fire Prevention Officer Roel Bus said three occupants in the one-and-a-half storey home were alerted to the blaze by smoke alarms, and escaped unharmed.
"The fire was contained mostly to the exterior of the building," said Bus.
He said the cause has been determined to be improperly discarded smoking materials.
"Even though it's very cold outside, it's still very important to discard your smoking materials in a metal container, a deep container that doesn't tip over," said Bus. "Even in these conditions, smoking materials could keep smouldering for a while, and if the right conditions come, and it turns into a flaming combustion, it can still cause a fire which in this case it did."
Bus said the preliminary damage estimate is $25,000.