A clothes dryer vent clogged with lint started a 2013 fire in East Gwillimbury, Ont., that killed four members of the same family, according to a fire marshal's report released Wednesday.

Kevin Dunsmuir, 55, his wife Jennifer, 51, and their sons Robert, 19 and Cameron, 16, died in March of last year after an early-morning fire broke out in their Howard Street home in East Gwillimbury, about 50 kilometres north of Toronto.

Another son, David, 24, is the only remaining member of the immediate family. He was away studying at Brock University in St. Catharines, Ont., at the time of the fire.

The report by Fire Marshal Ted Wieclawek pointed to a number of factors in the fire, including:

  • A dryer vent that was clogged with lint, causing the fire.
  • The lack of a main-floor smoke alarm, which delayed the family learning of the fire and calling 911.
  • By the time the second-floor alarm was activated, escape down the central staircase was no longer possible, leaving the family trapped on the second floor.

After the fire, there were questions raised about the fire department's response time and training. Here's how the report addressed that:

  • Response time was not an issue because survival was "untenable" due to the delayed detection.
  • There was no issue of training with the volunteer firefighters who responded.

An earlier fire marshal's report pointed to a compromised security system and the lack of a main-floor smoke alarm as factors in the fire.

In releasing his report, the fire marshal said the East Gwillimbury fire highlights the need for families to take the following precautions:

  • Develop and practise a fire escape plan for their home.
  • Identify who will help young people or anyone with physical or cognitive disabilities that may hinder their ability to escape.
  • Install smoke alarms on every floor and test them regularly.