JCS Enterprise Trailer Repair on Old McDonough Road was rattled Thursday morning after an apparent explosion. Captain Bentley with DeKalb County Fire Rescue said that a man was working on repairing the floor of a tractor trailer and was using cutting and wielding tools when the explosion happened. Others in the warehouse head a loud boom and saw flames. More News The worker was rushed to Grady Memorial Hospital with burns to his upper body. Fire crews confirmed that the man suffered burns to over 50 percent of his body, but was speaking to emergency responders as they treated him. Two other people were treated for smoke inhalation and one person twisted their knee. DeKalb fire crews arrived at the facility around 9:20 Thursday morning. As emergency crews worked on the injured man, firefighters stretched the water lines to the trailer that was on fire to get it under control. The cause of the explosion is still under investigation.