Three siblings were killed Tuesday morning in rural Rochester, Indiana, when they were hit by a pickup truck as they crossed a road to get to their school bus, officials said. Six-year-old twin boys and their 9-year-old sister were killed, Indiana State Police spokesman Sgt. Tony Slocum confirmed to CNN. An 11-year-old student who is not related to the siblings was also struck by the pickup and was airlifted to a hospital wi…