Thousands of signs calling out locations of fallout shelters are still posted across the five boroughs. Now, at a time when fears of nuclear war are slowly ticking up again, the city has begun removing them. NY1's Shannan Ferry filed the following report.

They're relics from another era. Faded fallout shelter signs put up more than 50 years ago during the height of the Cold War, when Americans were instructed and even drilled on what to do in case of a nuclear attack.   

But fallout shelters have not existed for decades, and the federal agency that established them - the Office of Civil Defense - no longer exists.  

So now one city agency, the education department, has begun removing fallout shelter signs that are still posted on their buildings.

Disaster preparation expert Jeff Schlegelmilch says that's a good idea, arguing the signs are so outdated they are misleading, especially at a time when some people are feeling anxious about the possibility of a nuclear explosion.

"With the threats from North Korea, and the nuclear tests people are looking at these, and not just as historical objects, but actually as indicators for a safe shelter," Schlegelmilch said.

Those anxieties ticked up on Tuesday when President Donald Trump tweeted that he has a nuclear button that is bigger and more powerful than that of the North Korean leader Kim Jong Un. 

Schlegelmilch says he thinks nuclear war is extremely unlikely but the shelter signs give New Yorkers a false sense of comfort they would have a place to go.  

He says building owners whose properties have the old shelter signs should follow the education department's lead in removing them. 

"What could happen is that you end up in the shadow of a mushroom cloud, running up to a building and the doors are locked and the shelter has not been in any sort of functional capacity for many decades," Schlegelmilch said.

So what should New Yorkers do in the event of a nuclear attack? The city Office of Emergency Management says to only get inside the nearest building, stay inside and "stay tuned for alerts".