It was the end of an era Tuesday when experts near Amarillo, Texas dismantled the United States' oldest and biggest nuclear bomb, the B53.

Officials say dismantling the bomb involved separating 136 kilograms of high explosives from a uranium “pit” at the heart of the weapon.

The Cold War relic, which was put into service in 1962, weighed 4,500 kilograms and was the size of a minivan. Military experts say its large size was meant to make up for its lack of accuracy. They say it was hundreds of times more powerful than the atomic bomb dropped on Hiroshima, Japan in 1945.

The weapon was the last in the arsenal of the B53 nuclear bombs. They were built at the height of tensions between the United States and Soviet Union, but are now obsolete because of the end of the Cold War, better technology, and arms control treaties.

U.S. experts refuse to say how many B53s were built before they were retired in 1997.

Tuesday's dismantling ceremony was part of President Barack Obama's goal to reduce the number and role of nuclear weapons in America's arsenal.