Virginia firefighters learn about the DOT-105J, a type of tank car used to transport chlorine, during a training course at a CSX rail yard in Richmond, Va., on Oct. 3, 2015.
Virginia firefighters learn about the DOT-105J, a type of tank car used to transport chlorine, during a training course at a CSX rail yard in Richmond, Va., on Oct. 3, 2015. Curtis Tate McClatchy
Virginia firefighters learn about the DOT-105J, a type of tank car used to transport chlorine, during a training course at a CSX rail yard in Richmond, Va., on Oct. 3, 2015. Curtis Tate McClatchy