No one quite knows what led to an Austell mobile home fire that killed a 20-year-old earlier this week, but police are working every lead possible.

“Right now we’re trying to go back and interview family and friends,” Cobb County police Sgt. Dana Pierce told Channel 2 Action News.

Landon Sides was found severely burned outside the home during the Thursday night fire, the station reported. Sides walked up the road to get help from friends, neighbors told Channel 2. He was taken to a hospital where he died from his injuries Sunday.

Police told the news station they are trying to determine what happened inside the home before the fire, but that may prove difficult since much of the residence was engulfed.

The Cobb County medical examiner and the fire and emergency services arson unit are working to determine the cause of the fire and how it spread to Sides.

Authorities are still trying to figure out how the fire started.