U.S. Navy Seabees assigned to Naval Mobile Construction Battalion 4 help assemble the foundation for the first of 75 temporary housing shelters in Pass Christian, Miss., on Sept. 24, 2005. The Seabees practice contingency construction projects like these shelters on a constant basis and can build as many as four in one day. Department of Defense units are mobilized as part of Joint Task Force Katrina to support the Federal Emergency Management Agency's disaster-relief efforts in the Gulf Coast areas devastated by Hurricane Katrina.