A Yonkers apartment building is boarded up today, one day after police say a teen caused a fire that left two dozen people homeless.Investigators say a teen living in the building at 81 Van Cortlandt Park Ave. is now facing charges for running an illegal marijuana growing operation that sparked the flames. Jason Fernandez, 19, has been charged with reckless endangerment, although police say he will likely face additional charges. Investigators confiscated high-powered heat lamps that they say overloaded the building's electric system.At his arraignment today, Fernandez's family said the fire was an accident and he feels horrible about what happens. They say Fernandez is a freshman at Bronx Community College, and before this, had never been in trouble with the law.Some of the nine families who were displaced by the fire are being assisted by the American Red Cross.Yonkers police: 20 homeless after marijuana grower sparks fire