On what type of vehicle was the singer of the song "Peggy Sue" killed?
{'directed': True, 'multigraph': False, 'graph': {}, 'nodes': [{'type': 'ANSWER_CANDIDATE_ENTITY', 'name_': 'Q3002150', 'id': 0, 'label': 'aircraft crash'}, {'type': 'INTERNAL', 'name_': 'Q5977', 'id': 1, 'label': 'Buddy Holly'}, {'type': 'QUESTIONS_ENTITY', 'name_': 'Q1454909', 'id': 2, 'label': 'Peggy Sue'}], 'links': [{'name_': 'P509', 'source': 1, 'target': 0, 'label': 'cause of death'}, {'name_': 'P175', 'source': 2, 'target': 1, 'label': 'performer'}]}