advising americans to move at least 50 miles away from the plant. japan has ordered evacuations at least 12 miles from the plant and now many americans are wondering about the safety of u.s. power plants, and they can't help but be reminded of the worst nuclear disaster right here in the u.s. at three mile island. let's bring in our mary snow. some painful memories being reawoken. >> reporter: painful memories, isha, but 33 years after the accident at three mile island there are few signs of the partial meltdown that occurred there and many people that lived through the accident never left the area. these stacks at three mile island rarely faze many of the residents here in central pennsylvania, but they evoke memories of a national might mayor. the site of the worst nuclear accident in america's history back in march of 1979. americans tuned in to the nightly news to hear this. >> good evening. the world has never known a day quite like today.