Natasha Hastings of U.S. on the starting block before the women's 400 metres heats during the 15th IAAF World Championships at the National Stadium in Beijing, China August 24, 2015. (Photo by Lucy Nicholson/Reuters)

An explosion at a petrochemical plant is seen in Rizhao, Shandong province, July 16, 2015. According to Xinhua News Agency, a fire broke out after the explosion, which was caused by a liquified hydrocarbon leak at the plant, on Thursday morning. There was no report of casualties yet. (Photo by Reuters/China Daily)