Bill Whitaker went to the heartland to report this story, to Ohio, where its attorney general says the heroin epidemic is the worst he has ever seen; Lesley Stahl reports on smart guns, which firearms advocates believe can lower the number of accidental shootings and suicides in the U.S. ; Scott Pelley goes to Mozambique Island, once a center for the slave trade, where teams from the National Museum of African American History and Culture and the Slave Wrecks Project locate underwater remains of a ship that was once used to hold slaves before sending them to the New World.
