LUCERNE (CBS SF) — A Lake County man remained hospitalized with severe burns Tuesday after a weekend explosion ripped apart an illegal butane honey oil backyard lab, authorities said.

The Lake County Sheriff’s Department said Northshore Fire Department responded to the report of a fire in a residence in 6000 block of First Avenue in Lucerne on Saturday night.

Arriving firefighters, found a shed on the property completely destroyed by an explosion and flash fire. They also found 36-year-old Jay Hofer standing in the driveway, suffering from severe burns to his face and chest.

He was transported to Sutter Lakeside Hospital, but then air lifted to a burn center outside the county.

Investigators determined that Hofer was illegally manufacturing a controlled substance inside the shed at the time of the explosion. Deputies have forwarded their findings to the Lake County District Attorney’s office for possible charges.