The Ontario Office of the Fire Marshall has finished its investigation into Friday's fatal house fire in Alexandria, saying there was no battery in the second-floor smoke alarm.

Investigators said the fire started on the porch, which blocked the only exit from the home.

While there was a working smoke alarm on the first floor, investigators said there wasn't a battery in the one outside the second-floor sleeping areas.

The fire claimed the life of 22-year-old Sarah Cholette and her three children – Maxime, Chloe and Jacob.

The father, 26-year-old Martin Desjardins, remains in the burn unit of a Toronto hospital.

The fire marshall's office says it's reminding residents to check their smoke alarms, install battery-powered smoke alarms or electric alarms with battery backup and practice home escape plans.

"Ninety per cent of fires in the home are preventable," added Kim Ayotte with Ottawa Fire Services. "Out of that, 48 per cent of these fires don't have a working smoke alarm and it's amazing that most people don't think it will happen to them."

There can be a $235 ticket or up to a $50,000 fine for individuals for not having working smoke alarms on every storey of the house and outside sleeping areas.

There's also a maximum fine of $100,000 for businesses if they don't comply.

The news release also mentioned two fatal fires in Toronto and Huntsville, Ont. this weekend, where there were no working smoke alarms in either residence.

With a report from CTV Ottawa's Ellen Mauro