Police are investigating a deadly shooting in Canarsie that left an 18-year-old man dead. According to authorities, the shooting happened at about 4 a.m. Sunday at Flatlands Avenue and Rockaway Parkway. When police arrived at the scene, they found the 18-year-old with a gunshot wound to the back and a 21-year-old who had been shot in the leg. Both were taken to Brookdale University Hospital and Medical Center, where the 18-year-old was pronounced dead.