Answer:
405 399 died
Explanation:
In the war 405 399 people died on the US side from which 78 750 were missing in action. The Vietnam war was a bloody and long war that was extremely hard to fight. There were no front lines and Vietnam soldiers used hit-and-run guerrilla tactics. In many raids of a few dozen men, Vietnam managed to cripple and kill many US soldiers without suffering much if any casualties themselves.