Curators make hard choices at New York 9/11 museum

"We're not here to traumatize our visitors," said Alice Greenwald, director of New York's 9/11 Memorial Museum that is due to open in its underground home at the Ground Zero site next year on the 11th anniversary of the attacks.

"Monumental artefacts are one thing, but we also have a human story to tell," Greenwald said.

Some of the most potentially disturbing exhibits are being set aside from the main exhibition spaces in special alcoves to allow visitors a chance to decide whether or not to view it.

It is here that museum curators have placed material such as images of people plummeting from the burning towers after the buildings were struck by airliners hijacked by al Qaeda militants, and a recording of the measured voice of a flight attendant aboard one of the planes moments before her death.

For museum curators, deciding whether to include examples of some victims' painful final moments was one of their toughest dilemmas as they sought to pay tribute to the nearly 3,000 people killed without piling more grief onto the living.

It's a familiar problem for people aiming to memorialize wars and atrocities.

"We're not just a history museum, we're also a memorial institution and so the tension that happens between commemoration and documentation is a flash point," Greenwald said in an interview at the museum's offices overlooking the ongoing construction of a facility that will occupy seven stories below ground at the World Trade Center site.