Feb. 7, 2012— -- Moments before Josh Powell ignited a gas-fueled explosion at his home, killing himself and his two children, a locked-out child services worker pleaded with a 911 operator to get police to the home because she feared for the two boys' lives.
Elizabeth Griffin-Hall, who had brought the boys to Powell's home for a supervised visit, called 911 after she said the man let the two boys into the house but slammed the door in her face.
"Nothing like this has ever happened before -- one of these supervised visits. I'm really shocked," she said in the 911 call, one of seven released this evening. "I can hear the kids crying but he still wouldn't let me in."
She told the 911 operator she wanted to move her car out of the driveway because she smelled gas coming from the house, and then asked for police to be sent to the home. But the 911 operator said officers only get sent to life-threatening situations.
"This could be life-threatening," she said. "He went to court on Wednesday and he didn't get his kids back. I'm afraid for their lives."
Moments later, with Powell's house engulfed in flames, she called back and told a 911 operator she believed he intentionally blew up the house, killing himself and his children.
That same day, Powell's distraught sister, Alina Powell, called 911 to say she was receiving "weird" messages from her brother via email and voicemail that made her too "terrified to drive over there" herself.
"I'm not afraid of him," she told the emergency operator through sobs. "He's never hurt me. I'm afraid of seeing something I don't want to see."
The deadly house explosion likely exceeded even her worst fears.
The frantic child services worker told the 911 operator that she brought the two boys to Josh Powell's home for the visit, but after he let the boys into the house he "slammed the door in [her] face" and then the house exploded.
"People are saying there's not somebody here," Griffin-Hall said in another 911 call after the explosion, "but I was just there, and there is somebody here. There's two little boys in the house and they're 5 and 7, and there's an adult man, and he has supervised visits, and he blew up the house and the kids."
When the 911 operator asked her if she believed he did it "intentionally," she answered, "Yes."
The call from Alina Powell was among the other tapes released today.
"He left me a voicemail," she said. "He said something about [how] he can't live without his sons and goodbye."
ABC News has exclusively obtained what is believed to be Josh Powell's final words to his loved ones, the voicemail he left for his family just 20 minutes before attacking his two young boys, Braden, 5, and Charles, 7, with a hatchet and igniting a gas leak that blew up his house on Sunday afternoon.
"I am not able to live without my sons, and I'm not able to go on anymore. I'm sorry to everyone I've hurt. Goodbye," the voicemail message said.
Police had called Josh Powell a person of interest in the disappearance of his wife, Susan Powell, who he claimed went missing from their Utah home after he and his then 2- and 4-year-old sons went on a midnight camping trip in December 2009.
He was never arrested or charged, but he lost custody of his sons after his father, Steven Powell, was arrested in September and charged with 14 counts of voyeurism and one count of child pornography. The pornographic images were kept in the home the two men shared with Josh and Susan Powell's boys.
According to investigators, Josh Powell withdrew $7,000 in cash the day before the explosion Pierce County Prosecutor Mark Lindquist told The Associated Press that detectives obtained Powell's bank records Monday, and that they are searching a storage unit he rented.
At a custody hearing last week, a judge said Josh Powell would have to undergo a psychosexual exam before he could get his kids back.
In another of the seven 911 calls just released, Jeff Bassett, Josh Powell's attorney, told the 911 operator about an email he received from his client.
"I understand he may have had an explosion. I may have some information," he told the operator after identifying himself.
When asked what information, he replied, "Just if it was an accident or if it was more than that. I got an email from my client and that could give every indication it was intentional. ... Basically, it says 'I'm sorry and goodbye.'"
Ed Wadagnolo, who said Powell worked for him, called 911 after seeing news of the house explosion and said he received a similar "strange email" that read, "I'm sorry. Goodbye."
Both Bassett and Wadagnolo said they received the emails at 12:05 p.m.
The tapes of the CPS worker, Alina Powell and Bassett were among seven released today. The others included frantic, fearful voices of people who heard the explosion, saw the house engulfed in flames and called 911.
A female neighbor told the 911 operator that there was "a loud, huge boom. And there's crap flying all over the place, dark smoke."
"Fire. Fire. There's a house on fire. Explosion," a male neighbor said. "The house is totally engulfed in fire, from front to back."
Stay with ABC News for continuing coverage of the Powell case and watch "Sins of the Father" on "20/20" Friday at 10 p.m. ET for an in-depth look at this family tragedy.