He was going to clean up the family's grave site, but simultaneously started South Korea's worst forest fire in history.
The police now suspect that a 56-year-old man unintentionally started the fires that killed 30 people and forced more than 27,000 to flee their homes.
The man's daughter has told the police how her father tried to burn tree branches hanging over the grave with a lighter. The wind caught the fire, which then spread.
Strong winds combined with drought got the fire to spread over large areas and the rescue services fought for several days to put out the fires.
