World War I officer who attended University of Iowa was probably killed in hours between armistice signing and cease-fire on November 11, 1918

From Kansas City Star:

One killed that day was Maj. Robert Mark Hanna of Kansas City, who was among nearly 11,000 men killed, wounded or missing on all sides on Nov. 11, 1918 - a staggering figure that exceeds the number of Allied casualties on D-Day in World War II. ...There is reason to believe, however, that Hanna was killed in action hours after the exhausted Germans certified that they were ready to give up. ...He studied law at State University in Iowa City, and in Kansas City he worked in insurance and real estate. ...

There is reason to believe, however, that Hanna was killed in action hours after the exhausted Germans certified that they were ready to give up. ...

Hanna was born in Ohio in December 1884, making him 33 when he died.