Unbelievable.

9/11 Museum, which sits on unidentified remains of attack victims, hosts alcohol-fueled party night before opening

On the eve of its grand opening to the public, the 9/11 Museum in lower Manhattan closed its doors to all but VIPs.

The sacred site that contains the remains of 1,115 unidentified victims became a private club for invited guests Tuesday night, sources told the Daily News — and some first responders were turned away during party preparations.

Former Mayor Mike Bloomberg and Cond Nast honchos were among those who nibbled crab cakes and shrimp cocktail hors d’oeuvres at the black tie affair, billed as a dedication ceremony, according to sources.

But one museum employee at the event, who spoke on condition of anonymity, described it as a festive affair.

“They were drinking, eating and laughing when this is pretty much a gravesite,” the employee said.

About 60 guests attended the soiree from 6:30 to 9:30 p.m.

The Information Desk on the museum’s lower level was converted into a bar for the night, the employee said.