MOORESVILLE, N.C. (AP) — Fire investigators have determined that a natural gas explosion destroyed Tennessee Titans cornerback Caleb Farley ‘s North Carolina home, killing the NFL player’s father and injuring a family friend, officials announced Tuesday.

It wasn’t clear where the gas leak originated, and the remaining structure is so unstable that the investigation into the cause and origin cannot continue, county officials said in a news release. The Iredell County Fire Marshal’s Office has finished its investigation into last week’s explosion and any further investigations will be conducted by the owner’s insurance provider.

Robert M. Farley, 61, was found dead in the debris of the house in Mooresville on Aug. 22, and first responders arrived to find family friend Christian Rogers, 25, exiting the collapsed structure, according to Kent Greene, director of Iredell County Fire Services and Emergency Management. Rogers was taken to a hospital with a concussion, he said.

Robert Farley was on a video call with a friend when the explosion happened, and the friend, who thought Farley had dropped the phone at first, could not get back in touch with him, Greene said .

Authorities had already ruled the blast accidental. Neighboring homes weren’t damaged.

County property records list the tax value of the home on a large plot near Lake Norman as nearly $2 million. Property records list Caleb Farley, who was born and raised in nearby Maiden, as the homeowner.

Caleb Farley, the No. 22 overall pick in the 2021 draft, was placed on injured reserve in November with a back issue. He has played 12 games in his first two seasons and is currently listed as physically unable to perform as the Titans wrap up training camp this week.