A pile of destroyed cars of teachers sits outside Briarwood elementary school in Oklahoma City, Oklahoma May 22, 2013. Rescue workers with sniffer dogs picked through the ruins on Wednesday to ensure no survivors remained buried after a deadly tornado left thousands homeless and trying to salvage what was left of their belongings. Curvature of horizon in the photo is due to an ultra-wide angle lens. (Photo by Rick Wilking/Reuters)

A worker pauses for a sandwich, resting on a girder during the construction of a skycraper. (Photo by Hulton Archive/Getty Images). Circa 1930

The attendants of the Sumptha Raja, Agra Durbar. (Photo by Hulton Archive/Getty Images). 1873

A leopard skin burns as Indian officials and activists burn wildlife contraband including tiger and leopard skins, and bones as part of a campaign to save the tiger in Mumbai, India, Tuesday, July 30, 2013. Despite conservation efforts, tiger numbers in India have declined due to rampant poaching of the cats for their valuable pelts and body parts that are highly prized in traditional Chinese medicine. (Photo by Rafiq Maqbool/AP Photo)

Activists stage a theatrical play where gay people are restrained by others wearing masks depicting Russian President Vladimir Putin, during a protest against Russia's new law on gays, in central London, Saturday, August 10, 2013. Hundreds of protesters, called for the Winter 2014 Olympic Games to be taken away from Sochi, Russia, because of a new Russian law that bans “propaganda of nontraditional sexual relations” and imposes fines on those holding gay pride rallies. (Photo by Lefteris Pitarakis/AP Photo)

Attendees visit the Ford booth during Auto China 2018 show held in Beijing, China, Wednesday, April 25, 2018. Auto China 2018, the industry's biggest sales event this year, is overshadowed by mounting trade tensions between Beijing and U.S. President Donald Trump, who has threatened to hike tariffs on Chinese goods including automobiles in a dispute over technology policy. (Photo by Ng Han Guan/AP Photo)

A woman walks on the stairs decorated with an image of two hands shaking to form the shape of the Korean Peninsula to support the upcoming inter- Korean summit, in downtown Seoul on September 17, 2018. South Korean President Moon Jae- in will fly to the North Korean capital on September 18, for his third summit with the North' s leader Kim Jong Un as a rapid diplomatic thaw takes hold on the peninsula despite stalled progress in denuclearisation talks between Pyongyang and Washington. (Photo by Jung Yeon-je/AFP Photo)

Steampunk enthusiasts attend the sixth annual Haworth Steampunk Weekend in Haworth, northern England on November 25, 2018. The three-day alternative lifestyle festival features: music, dancers, entertainers, burlesque performers, vintage vehicles, a fashion show and a masquerade ball. Steampunk is a subgenre of science fiction or science fantasy that incorporates technology and aesthetic designs inspired by 19th-century industrial steam-powered machinery. (Photo by Oli Scarff/AFP Photo)