The 9/11 Museum, which opened today after years of construction, sits 70 feet below sea level. Nestled into the bedrock that supports the entire city, it's protected by strong walls and great engineering—yet it, like so much of the city, will inevitably be threatened by rising tides.

Amidst dozens of fantastic stories about the museum today, one unpleasant but painfully relevant question remains: What about the water? The museum has already flooded once. During Hurricane Sandy, seven feet of seawater and debris rushed into the subterranean space, partially submerging artifacts like the last column of the World Trade Center and a fire truck from Ladder 3.


A worker clears debris at the 9/11 Museum after Hurricane Sandy. Image: AP Photo/Kathy Willen

There are no doubt plenty of contingencies for the next superstorm. After Sandy, the museum's directors reported that they were reconsidering final design details in order to put an unbeatable flood mitigation strategy into place:

The World Trade Center site's design includes elements that should help protect against flooding, but the Port Authority is re-evaluating that design because of Sandy, Mr. Plate said through a spokesman. "As we continue our assessments, we will implement additional strategic flood-mitigation efforts," he said.


That was cold comfort to families of the victims of 9/11, who fought tooth and nail (and lawyer) to prevent the remains of their loved ones from being placed inside the museum—in part because of the risk of flooding. "I can just picture these remains floating away with everything else," one family member told CBS at the time. "It is such a bad bad area to do anything, but certainly not to put something 70 feet below sea level."

Image: AP Photo/Craig Ruttle, File

The Museum will likely survive the coming storms, but future generations of New Yorkers will be forced to reckon with an inevitable truth: Much of NYC, including the Museum, could be threatened not just by storms, but by rising sea levels. As we learned this week, the collapse of the Antarctic Ice Sheet will raise global sea levels at least four feet—and if the sheet were to melt entirely, as much as 16.


According to Surging Seas, a sea level mapping tool based on peer-reviewed data, it would take roughly six feet of flood waters to submerge the western edge of lower Manhattan where the Museum is located. No one can really say how quickly that will happen—it could be a generation, or it could be many more.

Will the New Yorkers of the future spend billions of dollars on infrastructure that will protect the city and the museum from the rising waters? It's very, very likely. But even if they don't, there's an argument to be made that it doesn't matter: Memorials and museums, though we design them to be timeless, are temporal. They might last hundreds of years, but they—like the memories they honor and preserve—fade away over the millennia.


Image: Spencer Platt/Getty.

And that's OK. Someday, this remarkable museum may be underwater. Someday, we'll all shuffle off this mortal coil. But for the foreseeable future, this space will do its job—to remind—and for now, that's all that matters.


Lead Image: Spencer Platt/Getty.