This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

QUINTON, Okla. – After recovering the bodies of five workers who were missing after a drilling rig explosion in Pittsburg County, officials are now launching an investigation.

Around 9 a.m. Monday, emergency crews were called to an explosion at a well site about four miles southwest of Quinton.

Authorities say there were 22 workers on the well site, which was being drilled by Houston-based Patterson-UTI Energy.

A total of 17 workers were able to escape the explosion and ensuing fire.

Oil rig explosion in Quinton. (Photo Courtesy: Zayne Erickson)

One person was flown by helicopter to a Tulsa hospital with burn injuries, but five others couldn’t be found.

On Tuesday morning, officials identified the victims as 35-year-old Josh Ray, 29-year-old Matthew Smith, 26-year-old Cody Risk, 60-year-old Parker Waldridge and 55-year-old Roger Cunningham.

(Top left to right) Josh Ray, Matthew Smith, Cody Risk, (Bottom left to right) Parker Waldridge, and Roger Cunningham.

Officials with the Pittsburg County Sheriff’s Office say that the remains of all five workers were found around 2 p.m. on Tuesday.

Now, investigators are looking into how something like this could happen.

An initial report released by the Oklahoma Corporation Commission claims that there was an uncontrolled release of gas that caught fire. It also states that an employee attempted to shut down the well, but could not.

The U.S. Occupational Safety and Health Administration will lead its own investigation into the explosion, and the U.S. Chemical Safety Board announced that it will launch its own investigation.

On Thursday, the board announced that it will be “moving forward with a full investigation into the fatal gas well explosion.”

After the board learned about the explosion, officials say they sent two investigators to the scene to help the board make a decision regarding the scope of the investigation.

“Investigators arrived on site Wednesday morning and met with the lease holder for the well and the drilling operator. CSB investigators will continue to meet with well service providers and the well site consultant company that had employees on site at the time of the incident. Evidence preservation and collection is the initial focus of the investigation,” the CSB announced.