Jay Andrus, 25, a U.S. Marine veteran who trained in Ukraine with Hertweck, said the period his friend was listed as missing was difficult for family and friends to bear.
Hertweck, from California, traveled to Ukraine soon after Russia launched its full-scale invasion of the country in February 2022, initially assisting some of the millions of women and children who were fleeing the country in the earliest days of the war.
Hertweck was initially classified as missing in action and his family and fellow servicemen worked for months to retrieve his remains, which were believed to be behind Russian lines after the territory near the city of Avdiivka was captured by Moscow’s forces.
After returning to the United States for several months, he returned to Ukraine to receive a combat medical license, and trained Ukrainian troops before himself joining a combat unit as a medic.
At the funeral service in Kyiv’s Maidan Square, Hertweck's mother, father, sister and brother were presented with Ukrainian and U.S. flags as part of a military honors ceremony.