Josh Powell took the lives of his two sons in a house fire. Powell was a 'person of interest' in his wife's 2009 disappearance. NBC's Miguel Almaguer reports.
Updated at 7:58 a.m. ET
GRAHAM, Wash. -- The family of a Utah man suspected in his wife's disappearance of killing himself and his two boys
Authorities say the husband of a missing Utah woman intentionally set his home on fire Sunday, killing him and his two young sons shortly after the boys were brought to the home by a social worker for a supervised visit.
Neighbors had reported hearing an explosion, but Pierce County sheriff's spokesman Ed Troyer said Josh Powell's home was destroyed by a fast-moving fire that blew out several windows and was aided by some sort of accelerant.
Powell let the boys in the house, then blocked the social worker from entering, said Graham Fire and Rescue Chief Gary Franz.
The social worker called her supervisors to report that she could smell gas, and the home erupted in flames.
'I'm sorry, goodbye.'
Troyer said emails that Powell sent authorities seemed to confirm that Powell planned the deadly fire. Troyer didn't elaborate on the contents of the emails, but said they make police believe "this is intentional, this is planned."
Speaking to NBC's TODAY on Monday, Troyer characterized the incident as a "double murder-suicide."
A lawyer for Powell said he received a three-word email from his client just minutes before Powell and his two boys died in a house blaze. It said, "I'm sorry, goodbye."
Attorney Jeffrey Bassett told The Associated Press the email arrived at 12:05 p.m. Sunday, but he didn't see it until two hours later, when others informed him of the fire.
Authorities said they found three bodies in the home late Sunday afternoon as fire crews and police continued to search the rubble.
Sept. 29, 2011: Josh Powell could lose custody of his two sons.
"Everything we know right now, this has become a crime scene," Franz said.
Powell was under investigation in the disappearance of his 28-year-old wife, Susan Powell, from their home in West Valley City, Utah, in December 2009. He claimed he had taken the boys on a midnight excursion in freezing temperatures when she vanished.
The case took a bizarre turn last year after Powell's father, Steven, was arrested for investigation of voyeurism and possessing child pornography. Josh Powell was living at his father's home at the time, and a judge gave Susan Powell's parents custody of the boys, aged 5 and 7.
View images of the fire at NBC station King5.com
Last week, a judge ruled that the children of missing Utah mother Susan Powell must remain in the custody of her parents, and that they would remain with the grandparents unless their father agreed to undergo psycho-sexual evaluation.
Troyer said the elder Powell was put on suicide watch in custody after he was told of the deadly blast. "Steve Powell didn't seem very upset by the news, but was angry towards authorities who notified him," Troyer said.
Ted S. Warren / AP file
Josh Powell leaves a courtroom on Sept. 28 in Tacoma, Wash., after a judge awarded temporary custody of Powell's two sons to Susan Powell's parents.
Sherry Hill, a spokeswoman for the state Department of Social and Health Services, said the social worker who was with the children was not a Child Protective Services employee but a contract worker with a private agency that supervises visits for the state.
"The visit supervisor for this particular agency had taken the children to the home. When she does that, she sits through the visit and might take notes on her observations," Hill said. "She pulled up in the car, and the kids ran out ahead of her. He closed the door and locked it. She wasn't able to get in, and that's when she smelled gas."
"It's the most horrifying thing you can imagine happening," said lawyer Steve Downing, who represented Susan Powell's parents, Chuck and Judy Cox, in the custody fight. "The Coxes are absolutely devastated. They were always very fearful of him doing something like this, and he did it."
Downing also told the AP Sunday that the children had started talking to their grandparents about things they remembered from the night their mother vanished.
"They were beginning to verbalize more," Downing said. "The oldest boy talked about that they went camping and that Mommy was in the trunk. Mom and Dad got out of the car and Mom disappeared."
Bassett said he represented Powell free of charge because "every parent deserves the right to an attorney." Powell called or emailed him at least once a day, and often more than that, and in their conversations "he never once admitted doing anything regarding Susan. In fact, he denied it."
'Acting like little boys again'
Kirk Graves, 39, of West Jordan, Utah, Josh Powell's brother-in-law, said he and his wife, Jennifer, were stunned by the news. (Jennifer Powell Graves is Josh Powell's sister.)
Appearing on Monday's TODAY, Kirk Graves confirmed that his nephews had been "acting like little boys again" in recent months and were opening up about their memories of the day their mother disappeared.
"There was absolutely nothing anybody could've done to stop (Josh Powell)," he said. "He really only cared about himself. That's why he was able to do the things he did to Susan -- and the things he did yesterday."
Kirk Graves said he believed Powell was determined to "hurt everybody around him, and used the boys as a tool to do that.”
On Sunday, Graves said he and his wife think Josh Powell deliberately set the fire.
"His world was falling apart around him and he was going to lose his boys and get arrested for Susan's disappearance," he said. "He's a narcissist and he has no love for anyone but himself.
The Associated Press and Reuters contributed to this report.
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