Question: what event took place in fukushima japan after a tsunami
[{'answer': 'The Fukushima Daiichi nuclear disaster', 'provenance': [{'wikipedia_id': '31162817', 'title': 'Fukushima Daiichi nuclear disaster', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 34, 'bleu_score': 0.668740304976422, 'section': 'Section::::Abstract.'}]}]