A fire aboard a Virgin Atlantic flight headed to London forced the plane to make an emergency landing in Boston. Massachusetts State Police said in a news release that the crew extinguished the fire, which a preliminary investigation says probably started with a phone charger that ignited in a passenger seat. All 217 passengers on Flight 138 from New York as well as the crew were safely evacuated after landing. One passenger refused treatment for a smoke-related complaint. A Virgin Atlantic statement says the flight was bound for London’s Heathrow Airport. It was the second unusual landing at Boston’s Logan International Airport on Thursday. Earlier, an American Airlines jetliner from Chicago declared an emergency when a cockpit light indicated an unspecified potential mechanical problem as it approached the city, but the plane landed without incident.