High Quality Content by WIKIPEDIA articles! Three Mile Island Nuclear Generating Station (TMI) is a civilian nuclear power plant (NPP) located on Three Mile Island in the Susquehanna River, south of Harrisburg, Pennsylvania. It has two separate units, known as TMI-1 and TMI-2. The plant is widely known for having been the site of the most significant accident in United States commercial nuclear energy, on March 28, 1979, when TMI-2 suffered a partial meltdown. According to the US Nuclear Regulatory Commission, the accident resulted in no deaths or injuries to plant workers or members of nearby communities. The reactor core of TMI-2 has since been removed from the site, but the site has not been decommissioned.