The husband of missing Utah mother Susan Powell, Josh Powell, and their two sons died in an explosive house fire in a Graham, Washington, Fox News is reporting. The explosion comes after he lost custody of their children, who began talking about their mother more and suggested she was in the trunk of his car on the night she disappeared in 2009. Attorney Steve Downing told the Associated Press that Susan’s parents, Chuck and Judy Cox, said the two boys began talking to their grandparents more about the night their mother vanished.

Downing said his clients, who had custody of the children, said the Powell’s older son “talked about that they went camping and that Mommy was in the trunk. Mom and dad got out of the car and Mom disappeared.”

Josh sent a short email to his attorney minutes before authorities believe he set the fire, writing “I’m sorry, goodbye.” Pierce County sheriff’s Sgt. Ed Troyer said he hopes that investigators can fill in holes of the case. Autopsies will be performed on Josh and the children, and an arson investigation will be performed, as authorities believe Josh intentionally set the fire. The explosion came days after he was denied custody and ordered to undergo a psycho-sexual evaluation.

Sgt. Mike Powell from the West Valley City Police Department in Utah, who has no relation to the family, said it was too soon to say how Josh’s death may impact their investigation. “Quite frankly, this has obviously quickly unfolded up in Washington and we’re obviously just working through the details ourselves here.”

Written by: Karen Benardello