Mrs. Marie Graskamp of Milwaukee shows the different positions one might assume when entering the bomb shelter in Milwaukee September 3, 1958. This circular entrance is about three feet in diameter. This is the entrance (according to the builders) that would connect to the cellar of a home assuming the shelter was in the ground for added protection. If a bombing should occur, all members of family would proceed to the cellar and then through the circular port into the shelter. (Photo by AP Photo)

A man walks past a stranded public transport bus on a road flooded by heavy rains in Mumbai, India, August 5, 2016. (Photo by Shailesh Andrade/Reuters)

A towel with a print of the Nigerian naira is displayed for sale at a street market in the central business district in Nigeria's commercial capital Lagos February 4, 2016. (Photo by Akintunde Akinleye/Reuters)

Londoners sleep on the platform and on the train tracks at Aldwych Underground station,London, during heavy all night Nazi bombing raids, October 8, 1940. (Photo by AP Photo)

Students exercise in body training at Bishan Vocational Education Center in Chongqing, southwest China, January 13, 2016. These students were trained to be stewardesses of the high-speed train. (Photo by Xie Jie/Xinhua)

Visitors take photos of a child dressed in a traditional costume before a folk performance in Panyu, Guangdong province, China on April 20, 2018. (Photo by Reuters/China Daily)

A woman jumps with balloons while she poses for a picture at a park in Kiev, Ukraine May 6, 2018. (Photo by Valentyn Ogirenko/Reuters)

A dancer attends the final rehearsal for the new “VIVID Grand Show” at Friedrichstadt-Palast in Berlin, Germany, September 26, 2018. (Photo by Hannibal Hanschke/Reuters)