At 1:26 am a piercing notification came from the campus alert system, waking me from a light sleep while I was on call at the hospital. An active shooter. The computer screen in my call room glowed brightly. I was disoriented. I looked out the window at the hospital entrance. I saw nothing. I heard nothing unusual. I immediately texted my residents. “Where are you?” When they replied that they were safe in the ICU work room and call rooms,...