As America begins commemorating the 50th anniversary of the Vietnam War with events and ceremonies honoring those who served, a father and son, Richard B. Fitzgibbon Jr. and Richard III, from Weymouth are in a rare place in the long history of the conflict. One of only two confirmed father-son tandems to die in the war, their names are etched on the wall of the Vietnam Veterans Memorial in Washington, D.C., as well as on a more modest stone in the Vietnam Memorial Park in their hometown, seen at left.