New on SI: ‘Active Shooter!’ How Life Put Keanon Lowe Where He Was Supposed to Be

It’s an all-too-familiar alert in what should be America’s safest public spaces—and the decisions made by those facing without-warning terror can be the difference between carnage and survival. How would you react? Keanon Lowe knows, because on one fateful day in May, life led him right where he was supposed to be.