NEW YORK (Reuters) - New York City has quietly begun removing some of the corroding yellow nuclear fallout shelter signs that were appended to thousands of buildings in the 1960s, saying many are misleading Cold War relics that no longer denote functional shelters. The small metal signs are a remnant of the anxieties over the nuclear arms race between the United States and the former Soviet Union, which prompted U.S. President John F. Kennedy to create the shelter program in 1961 in cities across the nation. The signs, with their simple design of three joined triangles inside a circle, became an emblem of the era. While some New Yorkers may barely notice them today, to others they can be an uneasy reminder that the threat may have altered and diminished, but it has not vanished. Although the Cold War era has long ended, North Korea continues working to develop nuclear-tipped missiles capable of hitting the United States amid bellicose rhetoric from Washington and Pyongyang. A nuclear explosion is now seen as even less likely than during the Cold War. But should catastrophe ever strike, the signs, which still linger in their thousands, would be best ignored, city officials and disaster preparedness experts say.  In the aftermath of a nearby nuclear explosion, any survivors counting on the signs to lead them to safety from radioactive fallout after needlessly dashing outside would likely find themselves rattling locked doors or perhaps breaking into what is now a building s laundry room or bike-storage area. Maintenance of the shelter system, which once entailed federal funding to stock shelters with food and water, ended decades ago.  The removal of some of the signs from public school buildings, which has not previously been reported, is intended to partly reduce this potential confusion, according to the city s Department of Education. Michael Aciman, a department spokesman, confirmed that any designated fallout shelters created in the city s schools are no longer active and said that the department is aiming to finish unscrewing the signs from school walls by roughly Jan. 1. Although some of the tens of thousands of fallout shelter signs placed around the city by the federal government s Office of Civil Defense have vanished as old buildings have been renovated or demolished, city officials say this is the first coordinated effort to remove them. The Office of Civil Defense was eventually abolished in the 1970s, subsumed into the Federal Emergency Management Agency (FEMA). Aciman declined to say whether, given the signs are technically federal property, the U.S. government was consulted. But FEMA said it did not mind anyway.  FEMA does not have a position regarding the signs,  Jenny Burke, a FEMA spokeswoman, wrote in an email on Tuesday. Although the agency does not maintain lists of the old shelter locations, she added,  as a part of an ongoing planning effort, the agency is conducting research to retrieve Office of Civilian Defense records.      The city s removal appeared somewhat haphazard: on one Brooklyn street, a sign on a school photographed by Reuters this month was subsequently removed, while a second school a few blocks away still had its sign attached, albeit with a screw missing. As a history buff, Jeff Schlegelmilch is fond enough of the signs that he stuck a replica on his office door at Columbia University s National Center for Disaster Preparedness, where he is deputy director.  I love seeing the signs, but, as a disaster planner, they have to come down,  he said.  At best, they are ignored, at worst, they re misleading and are going to cost people s lives.  The consensus now, from the federal government downward, was that designated shelters were an outmoded concept, and updated contingency plans have been widely adopted since al Qaeda s attack on the United States on Sept. 11, 2001, Schlegelmilch said.  Were a nuclear explosion ever to happen, those far enough from the blast center to survive would do well to head to the lower interiors of any standard residential or commercial building, ideally a windowless basement, to shelter from radioactive particles outside, which can burn skin and cause serious illness and death. Cars, on the other hand,  are terrible,  Schlegelmilch said: the particles sail right through a vehicle s thin exterior. NYC Emergency Management, the agency that runs the city s disaster preparations, was not involved in the decision but staff there welcomed the signs  removal. Nancy Silvestri, the agency s press secretary, said even once the signs are gone from schools, many would remain on apartment buildings and other structures. City officials are uncertain who has jurisdiction over those, she said.  Eliot Calhoun, the agency s Chemical, Biological, Radiological, Nuclear, and Explosives Planner, sees the signs as unhelpfully muddying the waters.  He has spent years endlessly finessing a message, designed to flash as an alert on cellphones, that he hopes he will never have to send. In the nerve center of the agency s Brooklyn headquarters,  he called up onto a screen its current form:  Nuclear explosion reported. Shelter in basement/center of building, close windows/doors.   Every single time I look at it I change it a little bit,  he said.  When you only have 90 characters and you re trying to save lives you can really think too much about it.  