A runner who collapsed at the finish line after completing the Brooklyn Half Marathon died Saturday morning, according to police and fire department officials. The runner, who has not been identified, was pronounced dead at Coney Island Hospital shortly after 9:40 a.m., according to police. Police cited possible cardiac arrest, but are currently investigating the situation. Sixteen people were taken to the hospital, according to a final count from the fire department. Five people were reported to have serious injuries. Eight people had injuries that were not life threatening, and four others had minor injuries, the department said.