FRESNO, Calif. (AP) – Authorities in central California say a jail inmate who was injured in a gas pipeline explosion at a sheriff’s gun range has died.

The Fresno County Sheriff’s Office announced the 52-year-old man’s death late Monday, saying he suffered severe injuries in the April 17 blast. The office did not release his name or say when he died.

The explosion sent 11 people to the hospital, including eight jail inmates who were doing cleanup work at the range.

The blast occurred while a county employee was using a front-loader to build a dirt berm to confine gunfire to the range. Pacific Gas & Electric Co. says it appears the employee ruptured its pipeline.

The blast is being investigated by the California Public Utilities Commission.