Powell's children had been brought to the Puyallup, Wash. home by a foster-care caseworker for supervised visitation. When the worker arrived at the house, Powell "dragged" his boys inside, but refused the caseworker entry. She then called her supervisor.
The caseworker smelled a gas-like odor and, according to media reports, called 911, however as she was making the calls, the house exploded. Within three minutes firefighters arrived, but the house was fully engulfed by fire.
According to CNN
, Sgt. Ed Troyer, Pierce County Sheriff's Department spokesman, said the fire was intentionally set by the father. "This was all on him," Troyer said of Powell and the blast. "He set this up, he did it."
Troyer called the deaths "a double murder-suicide," reported the Seattle Times
The boys, Charlie and Braden, were 7 and 5 years old.
The blast occurred around 12:15 p.m. local time (PST), and at 4 p.m., the blaze was still "burning hot," Troyer said. Three victims were found and authorities do not believe anyone else was in the house during the time of the explosion.
"All the walls in the house were on fire, almost immediately," neighbor Ryan Mickle told CNN affiliate KIRO, adding that the blast "shook my whole house."I didn't hear anybody inside. It was quite a scene."
Josh Powell's wife and the boys' mother, Susan Cox Powell, went missing in Dec. 2009 when the family lived in West Valley City, Utah. Powell was a person of interest in her disappearance, as reported by Digital Journal
in 2009. The vanishing of Susan Powell has never been solved.
The boys have been in foster care and last week Powell's motion to get custody of his sons was denied by a Washington court. Powell has been involved in an "ongoing" custody battle with Susan Powell's parents, reported CNN.
Powell had lost custody of his sons after his father, Steven Powell, who resided with the family, was arrested
in Sept. 2011. The senior Powell was charged with one count of possession of depictions of minors engaged in sexually explicit conduct in the second degree and 14 counts of voyeurism.
The boys have been in the custody of Chuck and Judy Cox since the elder Powell was arrested.
Reportedly, Joshua Powell sent an email to his attorney, Jeffrey Bassett, shortly before the explosion; the 12:05 p.m. email said, "I am sorry, goodbye." Police have confirmed the existence of the email, but have not verified the sender, however, have no reason not to believe the communication came from Joshua Powell.
Seattle Times reported Pierce County Sheriff Paul Pastor told reporters near the house, "What happened here was a deeply wrong thing. It was an act of evil. Do not call it a tragedy because that sanitizes it. This was a terrible act of murder involving two young children."
According to King 5 News
, an attorney for the Cox family released a statement stating the Cox family is "devastated by this horrific event. The family is grieving and there are no words to adequately express the loss of their beloved grandsons, Charlie and Braden. The family is grateful for the prayers and thoughts of so many."
Investigators are examining the home tonight to determine the exact cause of the blast. West Valley, Utah officials will be coming up to Washington. It is unclear at this time whether or not Utah authorities had new evidence of Powell's involvement with his wife's disappearance and may have been preparing to file criminal charges.
Seattle Times reported, Sgt. Mike Powell (no relation to Joshua or Susan Powell), a spokesman for the West Valley City Police Dept., wouldn't comment whether charges were to be filed.