A workman sweeping the highest sidewalk in the world, the 81st story of the Empire State Building, the world's tallest building, to the top of which the greatest dirigible “Los Angeles” will attempt to moor, New York, New York, early 1930s. This photo was made 1,248 feet above street level. (Photo by Adam Glickman/Underwood Archives/Getty Images)

A model falls over on the runway in a design by Victoria Bliss during the Project NextGen show at Mercedes-Benz Fashion Week Resort 18 Collections at Carriageworks on May 16, 2017 in Sydney, Australia. (Photo by Stefan Gosatti/Getty Images)

Police officers clear the area near Borough market at London Bridge on June 3, 2017 in London, England. Police have responded to reports of a van hitting pedestrians on London Bridge in central London. (Photo by Dan Kitwood/Getty Images)

Cows rush through mud and water while jockey holds onto their tails, on March 12, 2016 in Padang, West Sumatra, Indonesia. For hundreds of years these farmers have competed in one of the worldís most oddest races in the hopes of showing off their cattle. Known as Pacu Jawi the traditional cow race takes place in Padang, West Sumatra, and has become the highlight of the year for locals. (Photo by Teh Han Lin/Barcroft Images)

A woman takes a selfie with “RoboThespian” at Robots, a major new exhibition at Science Museum in London, England on February 7, 2017. Exhibition showcases 500-year history of robots, with over 100 robots and the largest collection of humanoid robots ever displayed. (Photo by Tolga Akmen/Anadolu Agency/Getty Images)

The People of Mah Meri tribe at home at Pulau Carey village on December 03, 2016 in Selangor, Malaysia. The Mah Meri people are one 18 tribes of Orang Asal (indigenous people) living in west Malaysia. The Mah Meri are know for thei wood carvings and also for the richness of their songs and dances. (Photo by Yuli Seperi/Sijori Images/Barcroft India)

A storm trooper feeds a walker in the grass, taken in Glasgow, Scotland, December 2016. Tiny Storm Troopers and a mini Darth Vader are captured doing everyday activities – from taking a bath, to wrapping presents. Scottish Artist and Photographer, David Giliver created these scenes over a period of two years using toys and miniature props. (Photo by David Gilliver/Barcroft Images)

A citizen rides in smog on December 20, 2016 in Jinan, Shandong Province of China. Air quality index (AQI) readings exceeded 400 and some schools have suspended classes in Jinan. (Photo by VCG/VCG via Getty Images)