Firefighters said working smoke alarms helped four people escape a home on Prince of Wales Drive near Manotick after a fire started in the basement in the early morning.
The fire started in the basement laundry room at about 3 a.m. and quickly spread to the first floor of the two-storey home.
Fifteen fire trucks and 48 firefighters were able to knock down the blaze in about an hour, but not before the fire did extensive smoke damage to the home.
Ottawa fire services estimates the damage to the home and its contents at $300,000. Investigators are working at the scene to determine the cause.