Kaylub Giamanco is the father who stopped a school shooter in Bend, Oregon, a week ago. The teen gunman entered the school and killed three students and a teacher before Giamanco stopped him. In a new interview with Oregon Public Broadcasting, Giamanco describes the moments leading up to his heroic actions, how he felt after he took down the shooter and that day's larger tragedy.

When actor Christina Applegate revealed that she had been misdiagnosed with multiple sclerosis, it triggered not only an outpouring of empathy for her, but raised important questions about how often people are told they have the condition when they don't. William Brangham discussed why MS can be so difficult to diagnose with Dr. Michael Kornberg of Johns Hopkins University.