Hawaii is reinstating a decades-old, nuclear attack warning signal in an effort to prepare for a potential North Korean missile launch. According to a report issued by the Hawaii Department of Defense, residents should prepare to be sheltered for as long as 14 days, but "90% of the population would survive" a nuclear attack. North Korea is pursuing nuclear weapons and missile programs in defiance of UN Security Council sanctions and has made no secret of its plans to develop a nuclear-tipped missile capable of hitting the US mainland.