FIRESTONE, Colo. (CBS4) – Investigators in Weld County believe a butane hash oil lab may have caused last week’s home explosion in Firestone. The Frederick-Firestone Fire Protection District determined that the explosion on Jan. 21 at 9744 Roadrunner Avenue was accidental.

(credit: CBS)

The man injured in the explosion remains hospitalized in the Denver area and investigators have not been able to talk with him. His condition was not released.

READ MORE: Criminal History For Aurora Officer John Haubert Sounds Alarm On Hiring Process

Weld County Drug Task Force Commander Scott Smith said investigators served a search warrant at the home after the explosion.

“The main things that we found were approximately 80 marijuana plants. They were mature,”  Smith said.

(credit: CBS)

Investigators have not found paperwork to show that the homeowner was permitted to grow that many marijuana plants.

READ MORE: Casa Bonita Supporters Optimistic Of Potential Sale To South Park Creators Trey Parker & Matt Stone

The task force also found 16 pounds of processed marijuana at the scene and approximately 2 pounds of marijuana oil. The task force sent the oil to a lab to determine if it is THC or hash oil.

Hash oil extraction is illegal in Colorado if flammable materials are used, Smith explained.

The damage from the explosion was concentrated to the garage but spread to other parts of the home. The evidence led investigators to believe that a butane hash oil lab was likely located in the garage.

(credit: CBS)

Investigators will work with the Weld County District Attorney’s office to determine charges in the case.

MORE NEWS: MLB All-Star Game & Events Linked To Outbreak Of At Least 14 Fans

The Weld County Drug Task Force is a multi-jurisdictional team that includes members of the Greeley Police Department, Evans Police Department and Weld County Sheriff’s Office.

Audra Streetman