September 11 Memorial Museum prepares to open on May 21 May 14 2014

A museum commemorating the 9/11  is on the verge of opening, with familiar sights and artifacts never before shown on public display.

The doors open to the general public May 21.

The museum's two main exhibition areas, both underground, recall Sept. 11, 2001, when hijacked airplanes slammed into the World Trade Center's twin towers, the Pentagon and a field near Shanksville, Pa., killing nearly 3,000 people.

An "In Memoriam" exhibition, on the footprint of the World Trade Center's South Tower, commemorates the lives of victims

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A historical exhibition, on the footprint of the North Tower, focuses on the attacks, what preceded them and what has happened since.

Some of the most displays are wrecked emergency vehicles, nearly 2,000 oral histories and poignant personal items that belonged to victims.