Why is the death of Ted Lavender important to your understanding of the story in The Things They Carried?

Lavender's death is significant for two reasons. The first and most obvious is based on the central theme of what he carried. Lavender is described as a young boy who is afraid to die—and because of that reason, he carries a backpack full of tranquilizers and dope in order to dull the pain of his fear. Lavender's character is a direct representation of the youth that were drafted into the war: young men who were afraid and despondent and who turned to escapism via drugs to dull the effects of wartime. When Lavender is shot down, O'Brien notes that he falls especially hard because of the weight of his backpack, and later the men hope that his drugs numbed the feeling of his own death. These details illustrate the struggle faced by unwilling young people forced to fight, as well as the escapism those young people turned to.
Lavender's death serves as a wake-up call for the rest of the characters, as after Lavender is shot, Lieutenant Jimmy Cross decides to burn his photos of Martha and tells himself he will no longer fantasize about home. While the men may have criticized Lavender's incessant drug use, after Lavender's death, Cross is struck by the realization that by allowing himself to fantasize about his life and love at home, he is no better than Lavender shooting up tranquilizers to numb the pain. Lavender's death forces Cross to confront his present.