Quentin's plane (a Nieuport 28) was shot down in aerial combat over Chamery, a hamlet of Coulonges-en-Tardenois (now Coulonges-Cohan). He was felled by two machine gun bullets which struck him in the head. The German military buried him with full battlefield honors. Since the plane had crashed so near the front lines, they used two pieces of basswood saplings, bound together with wire from his Nieuport, to fashion a cross for his grave. For propaganda purposes, they made a postcard of the dead pilot and his plane. However, this was met with shock in Germany, which still held Theodore Roosevelt in high respect and was impressed that a former president's son died on active duty. According to his service record, the site was at Marne Grave #1 Isolated Commune #102, Coulongue Aisne. The French government posthumously awarded him the Croix de Guerre with Palm.