Law enforcement authorities load a body onto a vehicle following an explosion at a house in Graham
In an apparent murder/suicide Josh Powell, the husband of missing Utah woman Susan Powell, allegedly ignited a gas leak in his own home, killing him and his two children on Sunday. A DA has said he believes Susan Powell is dead. Authorities have been investigating her case as a likely murder, according to a report. REUTERS/Chris Goodenow

In an apparent murder-suicide Josh Powell, the husband of missing Utah woman Susan Powell, allegedly ignited a gas leak in his own home, killing himself and his two children on Sunday. Apparently they were beginning to speak about the fateful camping trip when she disappeared.

The Tragic End and the Children Speaking Out

Details are still emerging about the how and why Joshua Powell allegedly blew his house, killing his two sons. However, officials made it clear that they believe it was done intentionally.

However, reports indicate that the children began to speak out more about the incident.

Attorney Steven Downing said that Charles Powell, the oldest of the boys who was 4-years-old at the time of his mother's disappearance, began to discuss new details about the camping trip over two years ago.

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, reported Dowling, according to ABC.

A terrible timeline of the case led to the final, horrific end that claimed the lives of the Powell family:

Final Moments: The Conflagration

Fire authorities from Graham Fire and Rescue told the media that the incident occurred after Child Protective Services brought Powell's two boy from a supervised visit.

I'm sorry. Goodbye, wrote Powell in an email to his lawyer, before allegedly blowing up his own house, reported CNN. The Pierce County Sherriff's office believes that the Powell intentionally destroyed his house with him and his children inside.

This was all on him, said Ed Troyer, spokesman for the Pierce County Sherriff's office. He set this up. He did it.

In a story that captured nation's attention, Susan Powell has been missing without a trace since Dec. 7, 2009. For over two years, authorities have been investigating her disappearance discovering many twists and turns in the case.

So what are the facts of the case and what did authorities know about Josh Powell.

The Beginning: Susan Powell was first reported missing on Dec. 7, 2009.

Joshua Powell allegedly left his home for a night of camping with his two children, 4-year-old Charles and 2-year-old Braden, around 12:30 a.m. on Dec. 7, 2009. His wife did show up for work in the morning at her job at Wells Fargo Financial. All of her belonging were apparently left behind, reported Fox.

Joshua Powell Becomes Person of Interest

Police immediately began investigating the disappearance. On Dec. 9, police spent two hours searching Powell's home and removing certain items from the premises. Police did not consider Joshua Powell a suspect, but after two days, they ruled Susan's disappearance to be highly suspicious, reported Fox. On Dec. 16, police question Powell and deem him to be a person of interest connected to his wife's disappearance. Neighbors and some family members were reportedly not surprised with the turn of events.

Joshua Powell Creates, Facebook Groups and Offers Reward

In an effort to help find his missing wife, Powell created a website dedicated to her called On the website, Powell presented a theory that the disappearance of Utah Man, Steven Koecher, could be connected. He presented a list of parallels that allegedly links the two disappearances together.

Powell also took to social media in order to raise awareness about his wife's disappearance. However, on Jan. 30, 2010, the page was taken down for alleged technical reasons. The page was promptly re-established, with 45,000 members, reported KOMO- TV.

Steven Powell, Father of Joshua Powell, Arrested, Claims Susan Love Him

On Sept. 22, 2011, Steven Powell was arrested and charged with voyeurism. Police discovered he took thousands of photos of women and children. For years, he had privately followed women and children, snapping photos. The charges focused primarily on photos of two girls, ages 8 and 10, who lived in a house behind Steven. He would allegedly photograph them from his bedroom window, reported ABC.

However, photos of his missing daughter-in-law Susan were also discovered. A friend of Steven Powell, Sandy Anderson, claimed that he was obsessed with Susan and that he was addicted to pornography.

He'd talk about trying to see under her clothing, see her breasts. Even back then, he had this idea she was flirting with him, said Anderson, according to People. Steven Powell also claimed that the two were in love, reported ABC. Josh was apparently unaware of their alleged relationship.

Josh wasn't aware of a lot of these things at first because the first two or three years of his marriage -- it was really pretty much not something that really came to light, Steven Powell said. We interacted in a lot of sexual ways because Susan enjoys doing that.

Custody Battle Over the Children

After the allegations arose regarding Steven Powell, Joshua Powell became implicated with his father, although never charged. Susan's parents began a custody battle over the two children, who were living with Joshua and his father, reported Fox.

On Sept. 28, a judge ordered that Powell children stay with Chuck and Judy Cox, Susan's mother.

However, Joshua began fighting the case and on Dec. 7, 2011, the two year anniversary of his wife's disappearance, he renewed the custody battle for his young sons. On Feb. 1, 2012, Joshua was denied custody and ordered to undergo a psycho-sexual evaluation and a polygraph test, reported Fox.