It was the worst nuclear accident in U.S. history.
Forty years ago today, a terrified nation held its breath as technicians worked feverishly to prevent a nuclear meltdown at the crippled Three Mile Island nuclear plant in rural Pennsylvania.
A stuck valve shut down two pumps leaving tons of radioactive uranium sizzling. Workers failed to notice thousands of gallons of cooling water being drained from the reactor. Radiation leaked into the surrounding communities.
Four decades later, the debate continues whether the levels of radiation were high enough to cause a spike in cancers and other illnesses in people who lived near the plant.
Marvin Scott was at the plant covering the story the day of the accident in 1979 and he returned last week to see if the nuclear plant still poses a threat.