PARKLAND, Fla. (Reuters) - Students and teachers traumatized by one of the country’s deadliest mass shootings returned to classes on Wednesday with white ribbons and white roses to honor the 17 people killed by a gunman in their Florida high school two weeks ago. Marjory Stoneman Douglas High School reopened most of its doors for about 3,000 students at 7:40 a.m. EST (1240 GMT) for a half-day schedule. The building where most of the victims died will remain closed indefinitely.