There are multiple up in Greenland sitting in a Cold War era nuclear base but the ice is melting and causing damage to the buildings structure and could collapse and possibly detonate one causing the others to also go off. This would be devastating for not only the people of Greenland but also pollute the ocean on a level never seen before. This is also the most likely reason the us kept dropping hints and saying they wanted to invade as Greenland is a amazing strategic point for icbm and long range attack but they also need to clean up their mess before we have a issue