Video from EarthCam tracks the building of the National September 11 Memorial Hall and Museum from the ground up. (Courtesy of EarthCam)

The National September 11 Memorial Museum opened Thursday with a ceremony that featured President Obama, former New York mayor Michael Bloomberg, New York Gov. Andrew Cuomo (D) and New Jersey Gov. Chris Christie (R).

The museum, which spans 110,000 square feet of space, is an expansive exhibition site that contains multimedia displays, personal artifacts left behind and the remains of a stairwell that workers used to escape on Sept. 11, 2001.