ALLEN COUNTY, Ind. (WANE) -- The Allen County Sheriff's Department is investigating a fatal crash south of Fort Wayne Wednesday evening where one of the vehicles was driving down the wrong way on U.S. 27. Deputies are investigating near the intersection of U.S. 27 and Flatrock Road. Indiana State Police vehicles were also spotted at the scene. Authorities also sent out a mobile push notification just after 6:30 p.m. urging drivers to avoid the area. According to the Allen County Sheriff's Department, the crash involved a semitruck and two pickup trucks. One of the pickup trucks was heading north in the southbound lanes and crashed into the other pickup truck. The semitruck then crashed into both of the vehicles. The pickup truck heading down the wrong way on U.S. 27 caught fire following the crash, and the driver was pronounced dead at the scene, according to the Allen County Sheriff's Department. The driver of the other pickup truck was taken to a hospital in serious condition. Investigators are still combing the scene to determine exactly what happened, and the southbound lanes of U.S. 27 are expected to be closed for "several hours."