Four men were killed Thursday afternoon in a multiple vehicle accident caused by a tractor trailer. The fatal crash occurred in Midland, Texas at around 3 p.m. Authorities say a tractor trailer was eastbound on Interstate 20 when it crossed the median and collided head-on with a westbound tractor trailer. Both drivers, along with a passenger traveling in the westbound rig, were killed in the crash. Also killed in the wreck was a 50-year-old man, who was driving a 2003 GMC truck with a farm trailer attached. The man, who authorities said could not avoid a collision with the wreckage of the two tractor trailers, was pronounced dead at the scene of the crash. The accident started a fire that took the Midland Fire Department time to clear. A hazmat team was also at the scene to assist in clearing I-20. Investigators are at this time uncertain what caused the fatal tractor trailer crash.