One person was hospitalized Thursday morning after a crash involving a jackknifed semi-truck resulted in a major backup of traffic on the 91 Freeway in Fullerton. A Toyota Camry collided with the big rig in the incident, which was reported shortly before 4:30 a.m. near Magnolia Avenue, according to the California Highway Patrol. The driver of the sedan was uninjured, the CHP said. The Metro Cities Fire Authority said one person was transported to a hospital. All eastbound lanes were closed in the immediate aftermath of the collision. The Highway Patrol later opened three lanes as a heavy-duty tow truck crew began clearing the wrecked semi-truck from the scene.