STAMFORD — A 19-year-old Stamford resident was killed, and another person was seriously injured, when a silver BMW crashed into a tree Wednesday afternoon on Washington Boulevard near Scalzi Park. Stamford Police Sgt. Andrew Gallagher said the 19-year-old was a passenger in the vehicle when the crash occurred. The other injured party was the driver, he said, who was taken to Stamford Hospital and remains in critical condition.