LOS ANGELES – A catastrophic gas explosion blew the roof off a South Los Angeles welding shop early Friday, hurtling one victim to his death and electrocuting a second man on the street, fire officials said.

One victim “was blown from the inside to the outside” of the building and suffered fatal blast injuries, Capt. Steve Ruda of the Los Angeles County Fire Department told the Daily News.

Ruda said responders found the second victim under the axle of a vehicle and took him to a local hospital in critical condition.

“He was electrocuted trying to move his truck. A 34,500-volt power line fell on the truck, and he didn’t know the vehicle was energized. We found him by the vehicle,” Ruda said.

Firefighters quickly extinguished the blaze, and search dogs combed the smoldering wreckage for other victims but found none, Ruda said.

The search will continue as heavy equipment picks apart the rubble.

ndillon@nydailynews.com