The 21 Club, the venerated Midtown Manhattan restaurant, is famous for its clubby atmosphere and influential celebrity patrons, so it was strange recently to see its ornate iron gates padlocked and a sign explaining that the iconic place was closed because of water damage.

Stranger still was a walk inside “21,” during what would normally be a bustling weekday. The place was emptied of its clientele, and largely gutted of its well-appointed décor and furnishings, revealing its original gritty endoskeleton.

On Jan. 2, the restaurant flooded, causing damage that will keep it closed at least until March, with upper floor catering rooms closed at least until June.

Broken pipes near the ceiling on the fifth floor set off three fire sprinklers, sending thousands of gallons of water into the restaurant’s walls and floors and cascading four floors down the restaurant’s old wooden staircase “like Niagara Falls,” said Teddy Suric, the general manager of “21.”