Seattle Fire Department Investigators determined that the Fremont apartment fire that killed four children and an adult June 12 started when a foam mattress came in contact with a light fixture in a closet on the first floor.

Open doors and windows caused the fire to spread quickly from the first floor to the second floor of the two-story apartment at 334 N.W. 41st St., according to the Fire Department.

One woman and her 5-year-old niece escaped the fire, but heavy smoke and flames trapped four children and an adult woman in an upstairs bathroom. A 22-year-old woman, 13-year-old boy, 7-year-old girl, 5-year-old girl and 5-year-old boy lost their lives in the fire. Fire damage was estimated at $200,000.

The apartment had a smoke alarm system, and investigators were told that the smoke alarm did go off.

A mechanical problem on a reserve fire engine prevented the first firefighters on scene from being able to put water on the fire. The crew on Engine 18 was using a reserve engine the day of the fire while their first-line engine was undergoing routine maintenance.

The Fire Department is conducting a safety investigation into the fire and what went wrong with the reserve engine. Part of the safety investigation will include diagnostic testing on the reserve engine scheduled for early next week.

Parents and caregivers need information on how to keep their children safe and how to help them respond to a fire emergency, according to the Fire Department. Children need to know, at a level they can understand, what to do if a fire happens or the smoke alarm goes off, according to the department.

The Fire Department has developed a collection of activities and family worksheets for parents and caregivers here. These materials provide tools to help teach children what to do if a fire should happen in their home.