The only surviving son of Anne and Anthony Zambrano, Bernard Zambrano was a model of a young man, according to his relatives. On Monday, a plaque was installed on the Little Italy arch on Wooster Street, honoring the only known casualty of the Vietnam War from the Wooster Square neighborhood.

But a gap in his college education — he was studying to be a teacher at Southern Connecticut State College — made Zambrano eligible for the draft in 1968 and he was sent to Vietnam. “It was just all these fluke things that happened,” said his cousin, Paul Naclerio of Oceanside, Calif.