At 4:00am on March 28, 1979, a reactor at the Three Mile Island nuclear power facility near Harrisburg, Pennsylvania suddenly overheated, releasing radioactive gasses. During the ensuing tension-packed week, scientists scrambled to prevent the nightmare of a meltdown, officials rushed in to calm public fears, and thousands of residents fled to emergency shelters. Equipment failure, human error, and bad luck would conspire to create America's worst nuclear accident.