Investigators said Trenton Delisle, 3,  set fire to items in the living room of the mobile home. The fire killed him, his mother and his 2-year-old twin siblings.

This was the second fire the boy had set that morning, according to investigators.   Earlier, a bible was placed in the kitchen stove and caught fire. Survivor Amy Bouchard extinguished it before she walked her son to the nearby bus stop. 

When Bouchard returned to the home, it was engulfed in heavy smoke and fire. That second fire started in the living room.

Trenton Delisle would have turned 4 next week.
 
Investigators also said there were no working smoke detectors inside. The one smoke detector in the home did not have a battery.

A possible contributing factor was a large piece of Styrofoam that was blocking the rear door of the mobile home. Investigators said it was likely used for insulation.
 
The State Medical Examiner’s Office says smoke inhalation was the cause of the death of the three victims they had examined by early afternoon.