President Barack Obama and Sept. 11 survivors, rescuers and victims' relatives are expected to mark the opening of the 9/11 museum, where the story of the terrorist attacks is told on a scale as big as the twin towers' columns and as intimate as victims' last voicemails.
The National September 11 Memorial Museum is set to be dedicated Thursday before opening to the general public May 21.
By turns chilling and heartbreaking, the ground zero museum leads people on an unsettling journey through the terrorist attacks, with forays into their lead up and legacy. (AP)
Here's a look inside.