NEW YORK -- A 14-year-old boy who was "surfing" on the roof of a subway train was killed when his head struck an overhead beam and he fell to the tracks. Eric Alvarez of Harlem was found dead on the tracks between two stations in lower Manhattan at about 4:45 p.m. Monday, said Detective Carolyn Chew. While Alvarez was riding home from school, his friends dared him to climb to the top of the train, a practice known as "subway surfing," said Marisa Balde, a spokeswoman for New York City Transit. He apparently had climbed the rear of a car...