Firefighters watch as an air tanker drops retardant while battling the Ferguson fire in the Stanislaus National Forest, near Yosemite National Park, California on July 21, 2018. A fire that claimed the life of one firefighter and injured two others near California's Yosemite national park has almost doubled in size in three days, authorities said Friday. (Photo by Noah Berger/AFP Photo)

A riot policeman watches as a police vehicle burns in Braamfontein, Johannesburg, South Africa, Tuesday, October 25, 2016. Rioters in South Africa set a police vehicle on fire Tuesday and stoned vehicles near a Johannesburg university that has been the scene of sometimes violent protests by students demanding free education. The violence broke out in streets near the University of the Witwatersrand at around the same time that student protesters met and marched off the campus, South African media reported. (Photo by Yeshiel Panchia/AP Photo)

A history enthusiast, dressed as a soldier, fights during the re-enactment of Napoleon's famous battle of Austerlitz near the southern Moravian town of Slavkov u Brna December 5, 2015. Hundreds of history enthusiasts gathered near the city of Slavkov before a re-enactment of Napoleon's famous battle of Austerlitz on Saturday to mark its 210th anniversary. (Photo by David W. Cerny/Reuters)

An abandoned protection masks in the deserted building near bypass channel for cooling at the Chernobyl nuclear power plant in the Exclusion Zone, Ukraine, April 5, 20177. The Chernobyl nuclear accident occurred on 26 April 1986 in the No.4 light water graphite moderated reactor at the Chernobyl Nuclear Power Plant near Pripyat. An estimated 47,000 people of the city of Pripyat were evacuated after the explosion in 1986. (Photo by Vitaliy Holovin/Corbis via Getty images)

A Mai-Mai rebel soldier shows off his guns at a checkpoint near the Mugunga refugee camp in Zaire; 1996. (Photo by Carol Guzy/The Washington Post)

Three Japanese tourists had to abandon plans to drive to Stradbroke Island off the Queensland coast when their hire car became bogged in mangrove mud, on March 15, 2012 near Stradbroke Island, Australia. (Photo by Chris McCormack/Fairfax Media).

A girl laughs while unloading her boat of produce at a market in Ganvie on January 6, 2012 in Cotonou, Benin. Often called the Venice of Africa, Ganvie is a stilted fishing village on Lake Nokoue, near Cotonou in Benin, the largest such village in Africa, and home to approximately 20,000 residents. (Photo by Dan Kitwood/Getty Images)

An Israeli missile is launched from the Iron Dome missile system in response to a rocket launch from the nearby Palestinian Gaza Strip, on March 12, 2012 near Ashdod, Israel. (Photo by Uriel Sinai/Getty Images)