US Air Force warns against joke event to 'storm Area 51'

LAS VEGAS (AP) — The U.S. Air Force has warned people against participating in an internet joke suggesting a large crowd of people "storm Area 51," the top-secret Cold War test site in the Nevada desert.A prank event on Facebook that's attracted more than 1 million interested people suggests that a mass of people attempt to run into the mysterious site at 3 a.m. on Sept. 20.The site is part of the vast Nevada Test and Training Range and has become the center of UFO conspiracy theories.The