Question: when did the lead singer of boston die
[{'answer': 'March 9 , 2007', 'provenance': [{'wikipedia_id': '2016093', 'title': 'Brad Delp', 'start_paragraph_id': 16, 'start_character': 52, 'end_paragraph_id': 16, 'end_character': 66, 'bleu_score': 1.0, 'section': 'Section::::Death and aftermath.\n'}]}]