NEW YORK — A museum commemorating the September 11, 2001 attacks on New York and Washington is on the verge of opening, with wrenchingly familiar sights as well as artifacts never before on public display.

Among the first visitors to the National September 11 Memorial Museum are victims’ family members and others intimately involved in its creation who will attend on Thursday, after a Wednesday media preview.

The doors open to the general public on May 21.

The museum’s two main exhibition spaces, both underground, recall September 11, 2001, when hijacked planes slammed into the World Trade Center’s twin towers, the Pentagon and a field near Shanksville, Pennsylvania, 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.

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

A large hall displays a so-called slurry, or retaining, wall that survived the attacks and a 36-foot column from the Trade Center site covered with mementoes, inscriptions and missing posters.

The museum is the result of eight years of work, with input from curators, educators, architects, preservationists, victims’ family members, survivors, first responders, local residents, business owners and others.