Safety Department spokeswoman Melissa McDonald says the driver of the semi told troopers he thinks he fell asleep at the wheel as the rig rolled through Christiana in southern Rutherford County.
McDonald says the big truck ran into a pickup, then hit an above-ground diesel tank at the C-and-E Market and flipped onto its side, catching fire. It then struck two unoccupied vehicles and hit a pickup truck at the pumps, killing the man who was fueling it.
The truck also hit two vehicles which had one occupant each. McDonald says three people were injured.
The trucker was flown to Vanderbilt University Medical Center in Nashville, where he's reported in critical condition.
Two others were taken to Middle Tennessee Medical Center in Murfreesboro by ambulance.
Troopers say the truck was hauling air conditioners from Shelbyville.