The last two prisoners to leave the U.S. detention center at Guantánamo Bay were dead. On February 1, Awal Gul, a 48-year-old Afghan, collapsed in the shower and died of an apparent heart attack after working out on an exercise machine. Then, at dawn one morning in May, Haji Nassim, a 37-year-old man also from Afghanistan, was found hanging from bed linen in a prison camp recreation yard.