According to the The Seattle Times, a case worker delivered the boys to Powell's house Sunday near Tacoma, Wash., when Powell pushed the worker out of the house. Moments later, there was an explosion.
Officials have recovered three bodies from the house that they believe are Josh Powell and his sons Charlie, 7, and Braden, 5.
The case worker "was forced out, and an explosion happened shortly thereafter," Ed Troyer, spokesman for the Pierce County Sheriff's Office, told the newspaper.
The Associated Press reports that Powell's lawyer in his custody case, Jeffrey Bassett, received a three-word email from his client minutes before the explosion. It said, "I'm sorry, goodbye."
Only days earlier, a family court judge told Powell that he was not likely to get custody of the boys anytime soon, and that he needed to undergo a psychological review. The boys were in the custody of their grandparents, Chuck and Judy Cox.
Powell had denied any role in his wife's disappearance, and had told police that she went missing while he took the boys on an overnight camping trip in a snowstorm. He recently told the family court judge that Chuck and Judy were not taking good care of the boys and were turning their two sons against him.
Powell lost custody on Sept. 22 after his father, Steve Powell, was arrested and charged with possessing child pornography.