A lot of people are wondering if they would know what to do if an emergency alert like the one that scared many in Hawaii over the weekend popped up on their cell phones. The alert turned out to be a false alarm by someone who pushed the wrong button. A radiation safety expert says you can survive a nuclear attack, especially if you're half a mile or more from the epicenter. “If you can get inside and put 20 to 30 feet between you and the fallout, that distance will save your life,” he said. For more follow the hashtag #HowToSurvive