Nevada County sheriff’s officials say an explosion and fire at a house south of Grass Valley that injured occupants may have involved a butane honey oil lab.

Deputies responded about 11 a.m. Monday to the 11000 block of Alta Sierra Drive regarding a report of an explosion and structure fire. When deputies arrived, they met with fire personnel and observed several butane canisters that had been blown into the backyard of the residence and neighboring properties, according to a Sheriff’s Office news release.

Detectives from the Nevada County Narcotics Task Force were summoned due to the possible presence of a butane honey oil lab.

Narcotics detectives obtained a search warrant for the house and property. During the search, they recovered more than 50 butane canisters from the rubble as well as neighboring properties approximately 40 yards away. Sheriff’s officials said the fire and explosion caused the structure to shift downhill off the foundation, and investigation of the scene was limited due to the unsafe condition.

During the investigation, detectives learned that a 4-year-old child and other family members were inside the residence when the explosion occurred. They were eventually treated for injuries and released from Sierra Nevada Memorial Hospital.

Detectives conducted interviews at the scene and determined that Andrew Lugo also was in the basement area during the explosion. He reportedly was severely burned and fled before firefighters and sheriff’s deputies arrived. Fire personnel determined that the explosion and fire originated in the basement, based on the damage and fire pattern of the explosion.

Deputies learned that Lugo was connected to a second residence, in the the 11000 block of Table Meadow Road. They went to the address and found Lugo’s vehicle in the driveway, but no one answered the door. As of Tuesday, sheriff’s officials said, Lugo had not been found.