Video: Panic in classroom after students hear knock on door

CNN’s Adrienne Broaddus reports on the mass shooting at Michigan State University that left three students dead and five injured. The gunman died from a self-inflicted gunshot wound, police said.CNN’s Adrienne Broaddus reports on the mass shooting at Michigan State University that left three students dead and five injured. The gunman died from a self-inflicted gunshot wound, police said.