During the April 27th tornadoes in Alabama, a tornado passed within several miles of the Browns Ferry nuclear power plant, and severed the transmissions lines to the plant.
The shutdown was not as smooth as was first reported, and the majority of the emergency evacuation sirens in the area were not operational.
The Browns Ferry is identical in design to Fukushima unit 3.
http://www.nrc.gov/reading-rm/doc-collections/event-status/event/2011/20110428en.html#en46793
Since the shutdown, there have been further problems:
http://www.citizen-times.com/article/DN/20110516/NEWS11/110516015/TVA-reactor-loses-cooling-80-minutes-NRC-report?odyssey=nav|head