Where were you were when the Twin Towers fell in New York City? How about when 58 people were killed and 500 people were injured at the MGM Grand hotel in Las Vegas? Why is it that some mass casualty incidents stick with us while others do not? While we can instantly recall our location when the Twin Towers fell, we have a harder time with catastrophic events that fall short of mass-calamity. While we can all name a few events like MGM, Columbine and Sandy Hook, our memories quickly grow faint after tragedies. Do you recall the 2018 Santa Fe Texas High school shooting? Eight students and two teachers were murdered by a 17-year old student. Or, what about Community College in 2015? A 26 year-old student opened fire killing eight and wounding nine. I have no recollection of either event. But, why? Listen to find out.