"In 1999, Columbine High School in Littleton, Colorado, was the scene of one of the deadliest school shootings in United States history. Since that tragic day, hundreds of children and adults have been killed in our schools. So what's really going on in American classrooms?Oprah Show correspondent Lisa Ling took cameras inside a typical American high school. What she found was eye-opening, and what happens proves that real change and connection is possible."