The 1990 Interstate 75 fog disaster was a transportation accident that occurred on the morning of December 11, 1990 on a section of Interstate 75 (I-75) near Calhoun, Tennessee, during dense fog which obscured the visibility of motorists. The accident occurred in an area where fog is common and had been the site of previous multi-vehicle accidents caused by poor visibility. The accident consisted of a series of multi-vehicle collisions that ultimately involved 99 vehicles, and resulted in 12 deaths and 42 injuries. It was reportedly the largest motor vehicle accident in United States history when it occurred, in terms of the number of vehicles, and was the largest and second deadliest vehicle accident in Tennessee history to the 1972 Bean Station bus-truck collision, which killed 14. The d