Children, some in tears, are escorted down a road in Barcelona, Spain, Thursday, August 17, 2017. Police in Barcelona say a white van has mounted a sidewalk, struck several people in the city's Las Ramblas district. (Photo by Manu Fernandez/AP Photo)

N.C. Dezendorf, wife of the general manager of the Electro-Motive division of General Motors, christens the new lightweight “Aerotrain” at the company's locomotive works in La Grange, Ill. on August 22, 1955. (Photo by Edward Kitch/AP Photo)

A model presents a creation by British designer Vivienne Westwood as part of her Spring/Summer 2018 women's ready-to-wear collection show during Fashion Week in Paris, France September 30, 2017. (Photo by Charles Platiau/Reuters)

Igor Armicach, a doctoral student at Hebrew University's Arachnid Collection, looks onto giant spider webs, spun by long-jawed spiders (Tetragnatha), covering sections of the vegetation along the Soreq creek bank, near Jerusalem, Israel on November 7, 2017. (Photo by Ronen Zvulun/Reuters)

A member of the Air Force's Wings of Blue Parachute Demonstration Team salutes as he jumps out of an aircraft, during the opening ceremony of Aviation Nation 2017 Nellis Air and Space Expo at Nellis Air Force Base, Nev., November 10, 2017. (Photo by Senior Airman Kevin Tanenbaum/Reuters/U.S. Air Force)

Lily Aldridge and Stella Maxwell arrive at the Daily Front Row's 3rd Annual Fashion Los Angeles Awards at the Sunset Tower Hotel on April 2, 2017 in West Hollywood, California. (Photo by Jon Kopaloff/FilmMagic)

North Korean women soldiers take part in a military parade Saturday, April 15, 2017, in Pyongyang, North Korea, to celebrate the 105th birth anniversary of Kim Il Sung, the country's late founder and grandfather of current ruler Kim Jong Un. (Photo by Wong Maye-E/AP Photo)

A sewer cleaner of Dhaka City Corporation cleaning out the city's sewers on May 03, 2017 in Dhaka, Bangladesh. Despite a rise in the number of deaths of manhole workers every year, workers regularly go into the manholes without any protective gear. (Photo by Zakir Chowdhury/Barcroft Images)