CLARKSVILLE, TNA man suffered serious burns after an out-of-control car crashed into a gas pump Thursday morning.A pedestrian, Chris Porter, walking through the gas station parking lot was unable to avoid a fireball caused by the explosion and is seen in surveillance video rolling on the ground to extinguish flames on his legs.A car belonging to the station's owner also went up in flames after the crash.Porter was taken to Vanderbilt University Medical Center in critical but stable condition.Ward said he blacked out behind the wheel before the wreck. Hewas not injured, and the cause of the crash is still underinvestigation.