Fresno County deputies investigated the incident all night. They said a 24-year-old man was trying to turn marijuana into a condensed form, called "butane honey oil". The process involves using highly flammable chemicals that led to an explosion.
Deputies say the man suffered a head injury in the blast. He was taken to a hospital. His condition has not been released.
Deputies say the condensed form of marijuana is becoming a problem in Fresno County.