On the first day of the Battle of Messines, 7th June 1917, 6 Squadron experienced the highest number of flying casualties for any single day of the First World War, a statistic not to be equalled in the 103 years since the squadron was formed. Over a few short hours, four men were killed, three were injured and one was taken prisoner of war. The crew of one of the aircraft lost that day (RE8 Serial No A3214) were reported as 'Killed in Action', though their bodies were never