PHILADELPHIA — Three children and one man, believed to be their father, were killed early Sunday morning in a raging house fire in North Philadelphia, authorities said. Heavy fire was visible from both floors of a two-story row house on the 3200 block of Hartville Street in the city’s Kensington section when firefighters arrived shortly after 2 a.m., according to the Philadelphia Fire Department. “Despite an aggressive interior attack by firefighters, four people did not survive; three of them were children,” the Fire Department said in a statement issued Sunday morning. Their identities were …