A Southbury teen has been killed in a single-car crash.  Police responded to Roxbury Road near the Southbury Dog Park around 10:30 Monday night.  It was determined that 17-year old Ryan Rutledge's vehicle went through a wire rope guardrail, down an embankment and into the Pomperaug River.  The teen and a passenger were ejected from the Jeep.  A 16-year-old Woodbury girl was transported to the hospital for treatment of serious injuries.  Emergency responders say it appears the vehicle rolled over several times during the accident, which remains under investigation.