US Army soldiers, wearing the M40A1 Chemical-Biological Mask, from the First Infantry Division, 12th Chemical Company, wash an M997 High-Mobility Multipurpose Wheeled Vehicle (HMMWV) maxi-ambulance (4-litter) to remove left over chemicals. Soldiers performed a first aid and decontamination exercise at the town of Lukavac, Bosnia-Herzegovina. Operation JOINT GUARD, 27 June 1997