The highest-ranking military officer killed during World War II was Lieutenant General Simon Bolivar Buckner Jr., the commander of the Tenth Army during the Battle of Okinawa. He was killed by Japanese artillery fire on June 18, 1945.
Buckner's death was a significant loss for the Allied forces. He was a highly experienced and respected military leader, and his death came at a critical time in the war. Buckner's death highlighted the dangerous nature of warfare, even for high-ranking officers.
Buckner was posthumously promoted to the rank of four-star general, making him the highest-ranking American officer to be killed in action during World War II.