发生了什么事情？
这是俄罗斯历史上伤亡最惨重的潜艇事故。[{'character': '这', 'pinyin': 'zhe4', 'highest pitch': 10.41, 'lowest pitch': 9.14, 'duration': 0.21, 'prosody hierarchy': 'null'}, {'character': '是', 'pinyin': 'shiii4', 'highest pitch': 12.69, 'lowest pitch': 8.51, 'duration': 0.29, 'prosody hierarchy': '#2'}, {'character': '俄', 'pinyin': 'e2', 'highest pitch': 12.69, 'lowest pitch': 7.77, 'duration': 0.13, 'prosody hierarchy': 'null'}, {'character': '罗', 'pinyin': 'luo2', 'highest pitch': 10.26, 'lowest pitch': 9.04, 'duration': 0.15, 'prosody hierarchy': 'null'}, {'character': '斯', 'pinyin': 'sii1', 'highest pitch': 10.42, 'lowest pitch': 9.97, 'duration': 0.17, 'prosody hierarchy': '#1'}, {'character': '历', 'pinyin': 'li4', 'highest pitch': 10.44, 'lowest pitch': 8.69, 'duration': 0.18, 'prosody hierarchy': 'null'}, {'character': '史', 'pinyin': 'shiii3', 'highest pitch': 8.69, 'lowest pitch': 5.63, 'duration': 0.18, 'prosody hierarchy': 'null'}, {'character': '上', 'pinyin': 'shang4', 'highest pitch': 7.37, 'lowest pitch': 5.85, 'duration': 0.26, 'prosody hierarchy': '#2'}, {'character': '伤', 'pinyin': 'shang1', 'highest pitch': 8.88, 'lowest pitch': 8.48, 'duration': 0.27, 'prosody hierarchy': 'null'}, {'character': '亡', 'pinyin': 'uang2', 'highest pitch': 8.88, 'lowest pitch': 6.11, 'duration': 0.27, 'prosody hierarchy': '#1'}, {'character': '最', 'pinyin': 'zuei4', 'highest pitch': 10.12, 'lowest pitch': 7.97, 'duration': 0.2, 'prosody hierarchy': 'null'}, {'character': '惨', 'pinyin': 'can3', 'highest pitch': 9.0, 'lowest pitch': 4.31, 'duration': 0.28, 'prosody hierarchy': 'null'}, {'character': '重', 'pinyin': 'zhong4', 'highest pitch': 9.94, 'lowest pitch': 5.43, 'duration': 0.26, 'prosody hierarchy': 'null'}, {'character': '的', 'pinyin': 'de5', 'highest pitch': 13.42, 'lowest pitch': 5.73, 'duration': 0.14, 'prosody hierarchy': '#2'}, {'character': '潜', 'pinyin': 'qian2', 'highest pitch': 7.3, 'lowest pitch': 6.34, 'duration': 0.24, 'prosody hierarchy': 'null'}, {'character': '艇', 'pinyin': 'ting3', 'highest pitch': 7.3, 'lowest pitch': 5.03, 'duration': 0.17, 'prosody hierarchy': '#1'}, {'character': '事', 'pinyin': 'shiii4', 'highest pitch': 12.69, 'lowest pitch': 5.23, 'duration': 0.22, 'prosody hierarchy': 'null'}, {'character': '故', 'pinyin': 'gu4', 'highest pitch': 12.25, 'lowest pitch': 6.67, 'duration': 0.22, 'prosody hierarchy': '#4'}]