Complex sentence: The refugee column then proceeded towards the No Gun Ri area, from their homes, when they arrived at a U.S. roadblock, were searched for weapons or contraband and made to move to the parallel railroad tracks to clear the road for vehicle traffic.
Split into simpler sentences: The refugee column then proceeded towards the No Gun Ri area, from their homes. When they arrived at a U.S. roadblock, they were searched for weapons or contraband and made to move to the parallel railroad tracks to clear the road for vehicle traffic.