My husband and I were behind the pickup truck. Something must have happened to the driver going northbound as he drove from the middle of the two lanes( his vehicle was straddling the line) straight into the guard rail on the right side of the road, careened off of it into the beginning of the median guard rail, blew through it, over the grassy median and into the side of the tractor trailer where the was an instant fire burst. He could not have survived the hit at the median rail, in my opinion. It almost looked from behind that he could have slumped over the wheel and had his foot on the gas as his vehicle never slowed down and actually seemed to go faster as it went through that median barrier. You just got the feeling that he may have had a heart attack or some medical event.