Chandler, AZ — New details released on Tuesday morning show the apparent cause of last week’s building explosion in Chandler. According to Chandler police, the ATF determined that a natural gas leak is to blame for the explosion.

“The findings by the ATF National Response Team and investigative partners determined that the explosion was caused by an unintentional natural gas leak ignited by an independent ignition source,” stated ATF Special Agent in Charge Gabriel Pinon. Investigators have not determined what that ignition source was.

Chandler police also released new video of the explosion from the library right next door to the building that was destroyed.

Attorney Tom Ryan represents Platinum Printing and the three employees who were injured in the blast. They are brothers Dillion Ryan and Andrew Ryan plus Parker Mildebrandt. Tom isn’t related to the Ryan brothers.

He says he intends to file litigation against Southwest Gas because his clients’ lives are forever changed. “They’re left without a job, a source of income. They’ve been horribly disfigured, injured and burned,” says Tom. “They’ve done a lot of damage to these little families, and beyond that, too. It’s important to hold Southwest Gas accountable for their failure to adequately provide a safe gas system here in the City of Chandler.”

Chandler police released a video Tuesday from an explosion at a print shop last Thursday.

The fourth man hospitalized after the blast is Glenn Jordan. His wife says she is processing the latest information from investigators as she focuses on Jordan’s recovery.