Question: what is the deadliest tornado on record in the united states
[{'answer': 'Tri-State Tornado', 'provenance': [{'wikipedia_id': '454078', 'title': 'Tornado records', 'start_paragraph_id': 1, 'start_character': 99, 'end_paragraph_id': 1, 'end_character': 116, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '454078', 'title': 'Tornado records', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 756, 'bleu_score': 0.786312136400331, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7402913105873388894}, 'section': 'Section::::Abstract.'}]}]