A plane has crashed into a residential area in the US city of Buffalo, killing all 48 people on board and at least one on the ground.The turboprop aircraft, on a Continental Express flight, is understood to have come down in rain and sleet. It was en route to Buffalo from Newark, New Jersey and is said to have crashed some 10 kilometres short of the airport. Anxious relatives have been gathering at both airports. The relative of one woman passenger said: “My sister was on the plane as far as we know. I heard on the radio there had been a crash. So I called immediately to see if the plane had landed at the airport or not” . The crash site is in a populated area on the edge of farmland. Local media said one person on the ground had been killed. An emergency operation is continuing at the scene. It is not yet clear what caused the accident.