Question: where did the steel for the empire state building come from
[{'answer': 'Pittsburgh', 'provenance': [{'wikipedia_id': '9736', 'title': 'Empire State Building', 'start_paragraph_id': 25, 'start_character': 1028, 'end_paragraph_id': 25, 'end_character': 1038, 'bleu_score': 1.0, 'section': 'Section::::History.:Construction.\n'}]}, {'provenance': [{'wikipedia_id': '9736', 'title': 'Empire State Building', 'start_paragraph_id': 25, 'start_character': 0, 'end_paragraph_id': 25, 'end_character': 1338, 'bleu_score': 0.75160431565295, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 12054346087393052717}, 'section': 'Section::::History.:Construction.\n'}]}]