A large explosion closed both directions of a major highway in Central California and injured at least three people, authorities said Friday.
Traffic heading both north and south on Highway 99 in Fresno was halted by the explosion about 2:30 p.m., the California Highway Patrol reported Friday.
Three people were injured and two were flown out by helicopter for medical treatment, said Tony Botti, a spokesman for the Fresno County Sheriff's Office.
The explosion happened at the Fresno County Sheriff's gun range, where a work crew including county jail inmates using heavy equipment apparently hit a pipe carrying natural gas, Botti said. One of the workers appeared to be in critical condition, he said.
No law enforcement officers were injured, Botti said. A nearby rail line was also halted out of concern that a passing train could spark leaking gas.
Witnesses reported seeing a large fireball, said Pete Martinez of the Fresno Fire Department. The flames prompted a two-alarm call of firefighters.
The CHP asked drivers should use alternative routes. It's unclear when the highway will reopen.