A worker suffered severe burns in an explosion while he was repairing a semitrailer in DeKalb County, GA.

The explosion occurred at a tractor-trailer repair factory in the 4300 block of Old McDonough Road, DeKalb County Fire Rescue spokesman Dion Bentley said from the scene.

Initially, officials said the fire started after the semitrailer crashed into the building. 

Investigators later determined “the injuries were suffered when the patient was working on a trailer, cutting and welding on one of these tractor-trailers you see right there,” Bentley said.

The victim suffered burns over 50 percent of his body, he said. He is in the Grady Memorial Hospital burn unit in critical condition.

Bentley said people on the scene heard a large boom before the fire, which remains under investigation.

The factory is located near Conley in the southwest corner of DeKalb County.

Source: The Atlanta Journal-Constitution