Measles cases are higher in the U.S. than they've been in a decade, mostly because more and more nervous parents are refusing to vaccinate their kids. Contributing Editor Susan Burton tells the story of what happened recently in San Diego, when an unvaccinated 7-year-old boy returned home from a trip to Switzerland, bringing with him the measles. By the end of the ordeal, 11 other children caught the disease, and more than 60 kids had to be quarantined. (22 minutes)