Workers install main cables at the construction site of the Yangsigang Bridge crossing the Yangtze River in Wuhan, capital of central China's Hubei Province, June 25, 2018. The construction site is at an height of more than 200 meters. (Xinhua/Xiao Yijiu)

Workers work at the construction site of the Yangsigang Bridge crossing the Yangtze River in Wuhan, capital of central China's Hubei Province, June 25, 2018. The construction site is at an height of more than 200 meters. (Xinhua/Xiao Yijiu)

Yang Rengcai, a 50-year-old worker, installs main cables at the construction site of the Yangsigang Bridge crossing the Yangtze River in Wuhan, capital of central China's Hubei Province, June 8, 2018. The construction site is at an height of more than 200 meters. (Xinhua/Xiao Yijiu)

Workers take a break from work at the construction site of the Yangsigang Bridge crossing the Yangtze River in Wuhan, capital of central China's Hubei Province, June 25, 2018. The construction site is at an height of more than 200 meters. (Xinhua/Xiao Yijiu)

Workers take an elevator to the construction site of the Yangsigang Bridge crossing the Yangtze River in Wuhan, capital of central China's Hubei Province, June 10, 2018. The construction site is at an height of more than 200 meters. (Xinhua/Xiao Yijiu)

Workers pose for a photo at the construction site of the Yangsigang Bridge crossing the Yangtze River in Wuhan, capital of central China's Hubei Province, June 8, 2018. The construction site is at an height of more than 200 meters. (Xinhua/Xiao Yijiu)

Workers work at the construction site of the Yangsigang Bridge crossing the Yangtze River in Wuhan, capital of central China's Hubei Province, June 8, 2018. The construction site is at an height of more than 200 meters. (Xinhua/Xiao Yijiu)

Feng Kui, a 25-year-old worker, returns to the ground after a day's work at the construction site of the Yangsigang Bridge crossing the Yangtze River in Wuhan, capital of central China's Hubei Province, June 25, 2018. The construction site is at an height of more than 200 meters. (Xinhua/Xiao Yijiu)

An aerial photo taken on June 25, 2018 shows the construction site of the Yangsigang Bridge crossing the Yangtze River in Wuhan, capital of central China's Hubei Province. The construction site is at an height of more than 200 meters. (Xinhua/Xiao Yijiu)

A worker handles construction materials at the construction site of the Yangsigang Bridge crossing the Yangtze River in Wuhan, capital of central China's Hubei Province, June 8, 2018. The construction site is at an height of more than 200 meters. (Xinhua/Xiao Yijiu)

Workers install main cables at the construction site of the Yangsigang Bridge crossing the Yangtze River in Wuhan, capital of central China's Hubei Province, June 25, 2018. The construction site is at an height of more than 200 meters. (Xinhua/Xiao Yijiu)