COEUR D’ALENE, Idaho — A man who set a wildfire and then fatally shot two firefighters and wounded another in northern Idaho was a 20-year-old transient who attacked the first responders after they asked him to move his vehicle, a sheriff said Monday.

Firefighters were ambushed by a gunman while responding to a brush fire in Coeur d'Alene, Idaho, on Sunday, according to the local sheriff's office.