A South Korean man tending a family grave is suspected of sparking one of the ‘unprecedented’ wildfires that ravaged the southeastern part of the country last week, the National Police Agency said Monday.

South Korean firefighters were able to fully contain the wildfires that have ravaged the southeastern part of the country and left 30 dead, officials said, while authorities began a joint investigation into the cause.

South Korean police plan to question a 56-year-old man on suspicion of starting at least one of the wildfires that recently devastated the country’s southern regions, killing 30 people and burning more than 119,