Two huge explosions tore through an industrial area where toxic chemicals and gas were stored in the northeast Chinese port city of Tianjin, killing at least 50 people, including at least a dozen fire fighters, officials and state media said on Thursday. At least 700 people were injured, more than 71 seriously, the Tianjin government said on its Weibo microblog, and the official Xinhua news agency said two fires were still burning. Wednesday nigh…