The young sons of Susan and Josh Powell, who died with their father when he ignited an explosion in their Washington home, were beginning to verbalize that their mother was in the trunk of their father's car on the night that she disappeared in 2009, a lawyer for the missing woman's parents said.
Attorney Steve Downing told the Associated Press that Braden and Charles Powell, who were 2 and 4 at the time of Susan Powell's disappearance, were beginning to tell their grandparents details about the night that their father took them on a late-night camping trip during a blizzard, including the fact that their mother disappeared after leaving in the car with their father.
"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."
Sgt. Mike Powell of the West Valley City Police Department in Utah did not return phone calls inquiring about the children's assertions about their mother's presence on the December 2009 camping trip, AP reported.
"Quite frankly, this has obviously quickly unfolded up in Washington and we're obviously just working through the details ourselves here," Powell, who is not related to the family, said earlier on Sunday.
Josh Powell set off an explosion at his home Sunday that killed himself and his two sons, who were there for a supervised visit.
"We believe that he killed his kids and himself," Pierce County, Wash., Sheriff's Department spokesman Sgt. Ed Troyer said Sunday.
Josh Powell's lawyer, Jeffrey Bassett, said he received an email from his client minutes before the explosion that said "I'm sorry, goodbye," but he didn't see it until two hours later, when he was informed of the blast.
Bassett told AP he knew his client was upset about being denied custody of his sons at a court hearing last week, when he was ordered to undergo a psychosexual evaluation and polygraph test in order to get them back.
Graham, Wash., Deputy Chief Gary Franz told ABC News that a Child Protective Services (CPS) worker had just dropped off Powell's two sons at the house for a supervised visit. Powell took his two sons inside the house and then locked the CPS worker out.
"The children were just right in front of her as she was walking up to the door," Child Protective Services spokeswoman Sherry Hill said. "They went into the house and Josh shut the door right in front of her and locked it."
The CPS worker smelled gas, stepped away and the house exploded. The case worker was not physically harmed.
"He grabbed the kids, locked her out of the house, and immediately the house went up in flames, very quickly, very big, so we believe that Josh Powell intentionally set this fire," Troyer said.
Firefighters arrived at the scene and found the three bodies. Police are awaiting verification from the Medical Examiner's Office, but said they believe the bodies are those of Josh Powell and his two sons.
Troyer told ABC News affiliate KOMO-TV in Seattle that emails Powell sent to authorities seemed to confirm that Powell planned the explosion. Troyer did not elaborate on the contents of the emails.
The house, which was on a dead end in a quiet residential neighborhood, has burned down to a charred frame.
Josh Powell is the only named person-of-interest in Susan Powell's 2009 disappearance, but he had not been charged. The couple's two sons were placed in custody of Susan Powell's parents in 2011 after Josh Powell's father, Steve Powell, was arrested on charges of voyeurism and child pornography.
At a hearing Wednesday, a statement from the West Valley City, Utah, police noted that information and images were found on Josh Powell's computer that "specifically related to their children's welfare," according to ABC affiliate KTVX in Salt Lake City.
The police did not specify what the information was, but Judge Kathryn J. Nelson ruled that because of that information, Josh Powell would not be allowed to have his children back until he submitted to a psychosexual evaluation and a polygraph test, the report said.
Bassett, Josh Powell's attorney, said the ruling was unfair to his client, who has not been charged with any crimes.
"Utah was dangling the alleged content of this disk. If this disk contains what they're saying it contains why haven't they arrested my client?" he said at the hearing.
The children were to remain with Chuck and Judy Cox until Josh Powell's next hearing, which was scheduled for July. Josh Powell was allowed twice-weekly supervised visitations with his sons during that time, KTVX reported.