Two Interstate-55 accidents — one fatal — halted traffic at the 86 and 85 mile markers for a couple hours early Friday in Scott County .At 7:11 a.m. Friday emergency crews responded to a tractor trailer on fire in the median at the 86.6 mile marker of Interstate 55. According to the Missouri State Highway Patrol, the tractor trailer driven by Antoinne L. Simpson, 45, of Southaven, Mississippi, was traveling southbound when his vehicle ran off the left side of the road, struck cable barrier and a concrete bridge pier. The vehicle caught fire. Debris from the tractor trailer then struck the northbound vehicle driven by Donald W. Massey, 52, of Sikeston, Missouri. Simpson was pronounced dead at the scene at 8:33 a.m. by Scott County Coroner and taken to the Scott County Morgue. Both southbound and northbound lanes were blocked and traffic was being diverted to the Kelso/Scott City exits. Then at 8:55 a.m., a second crash occurred at the northbound 85 mile-marker when an SUV operated by Nicholas L. Nation, 28, of Scott City, Missouri, rear-ended a tractor trailer, which was stopped in traffic, and driven by Ryan J. McAdoo, 38, of Marion, Arkansas who was stopped in traffic. Nation received serious injuries and was flown to a St. Louis hospital. Traffic was then diverted at the Benton exit.