Nuclear power station near Harrisburg, Pa.
, site of the most serious accident in the history of the U.S. nuclear power industry (March 28, 1979). Mechanical failures and human errors caused a partial meltdown of the nuclear core and the release of radioactive gases. Despite assurances that there had been little risk to people's health, the accident increased public fears about the safety of nuclear power and strengthened public opposition to its use, effectively stopping construction of nuclear reactors and further development of U.S. nuclear power plants.