By comparison, the nuclear bomb the United States dropped on Hiroshima in 1945 released an estimated 15 kilotons of energy.

CNN: Russia starts clean-up after meteor strike

The U.S. space agency, NASA, said the meteor released nearly 500 kilotons of energy, about 33 times more than the nuclear bomb the United States dropped on Hiroshima, Japan, in 1945.

CNN: Russian scientists track down fragments of Urals meteor

The site produced plutonium for the bomb dropped on the Japanese city Nagasaki and continued producing plutonium for the US nuclear arsenal for years.

FORBES: Nuclear Waste Leaks Worse than Thought in Washington