A blast at a fireworks factory in China’s Hunan province has killed 21 people and injured 61, prompting a call from President Xi Jinping for a thorough investigation, state media reported on Tuesday. The explosion in Liuyang, under the administration of Hunan’s capital city of Changsha and a hub for fireworks manufacturing, occurred on Monday at around 4:40 pm (0840 GMT), according to reports by CCTV and Xinhua. Social media footage showed massive plumes of smoke billowing up into clear blue ski