At dawn on September 11, 2001 in Mount Vernon, New York, a man wakes, dresses, pulls black high-top trainers onto his feet, kisses his sleeping wife and heads to work in the north tower of the World Trade Center. Meanwhile in Queens another man — a pastry chef at Windows on the World, the twin towers’ top-floor restaurant — puts on jeans, a blue checked shirt and a Casio watch handed to him by his wife. She drives him to the station, where he waves goodbye, disappearing down the subway steps. In New York City and its suburbs more than...