A man salts a downtown sidewalk in Washington, Thursday, March 5, 2015, as snow begins to fall. The U.S. federal government said its offices in the Washington area will be closed Thursday because of a new round of winter weather expected in the region. The Office of Personnel Management said non-emergency personnel in and around Washington were granted excused absences for the day. Emergency employees and telework-ready employees were expected to work. (AP Photo/Andrew Harnik)

Young gymnasts practice pull-up on a bar at a gymnasium of a sports school in Jiaxing, Zhejiang province April 11, 2015. (Photo by William Hong/Reuters)

In this Saturday, July 4, 2015 photo, Israeli and Russian members of knight clubs cook their breakfast before the reenactment of the Battle of Hattin in Lavi Forest, northern Israel. About a third of the participants arrived with their elaborate gear from Russia. The project is supported by the Lower Galilee Regional Council. (Photo by Oded Balilty/AP Photo)

Revellers pose during the 24th Street Parade dance music event in Zurich, August 29, 2015. (Photo by Arnd Wiegmann/Reuters)

A girl wearing a butterfly headband poses for a picture near damaged buildings in the rebel held besieged city of Douma, in the eastern Damascus suburb of Ghouta, Syria January 19, 2017. (Photo by Bassam Khabieh/Reuters)

A young couple rest in a football field after a forest fire devastated Santa Olga, 240 kilometres south of Santiago, on January 26, 2017. Six people – among them four firefighters and two police – have now been killed battling vast forest fires in central Chile, officials said Wednesday. Multiple blazes have ravaged 238,000 hectares (588,000 acres) and are growing, the National Forestry Corporation said in a statement. (Photo by Pablo Vera Lisperguer/AFP Photo)

A competitor shouts as he takes part in the “Tough Guy” adventure race near Wolverhampton, central England, on January 29, 2017. The Tough Guy event, which is being held for the final time in its 30th year, challenges thousands of competitors to run a gruelling course whilst negotiating over 200 obstacles including: water, fire, and tunnels. (Photo by Oli Scarff/AFP Photo)