An 18-wheeler caught fire on I-240 in Shelby County overnight. The incident is causing some backup Tuesday morning. The truck was heading eastbound on I-240, then went up in flames between Walnut Grove and Poplar. Flames had consumed the truck by the time WMC Action News 5 crews arrived on the scene. Thankfully no one was hurt. The Memphis Fire Department was able to get the blaze under control in about an hour. Some lanes are still shut down in the area.