A weapon is being destroyed during an exercise to disable seized weapons in Caracas, Venezuela August 17, 2016. (Photo by Marco Bello/Reuters)

A walker has left a handprint on a snow- covered tree trunk on Grosser Feldberg mountain in the Taunus mountain range, Germany, 16 January 2017. (Photo by Frank Rumpenhorst/DPA)

A news crew runs from flames southeast of Middletown, Calif., on Tuesday, September 15, 2015, as winds kick up the Valley fire. (Photo by Wally Skalij/Los Angeles Times/TNS)

Children guarded by Hungarian police play on the ground after being detained along with other migrants who illegally crossed from Serbia to Hungary near the village of Asotthalom, Hungary, September 16, 2015. (Photo by Dado Ruvic/Reuters)

French photographer Laurent Chehere's “Flying Houses” exhibit takes workaday houses and lets them lift the imagination. The exhibit is showing at the Muriel Guépin Gallery in New York. Photo: Laurent Chehere's “Flying Houses”: “The Great Illusion”. (Photo by Laurent Chehere)

Zookeepers measure the length of a pueblan milk snake in the Reptile House of ZSL London Zoo as part of their annual weighing and measuring of their animals on August 25, 2011 in London, England. The heights and weights of over 750 different animal species at the zoo are recorded into the International Species Information System, to monitor their health and share the data with other zoos across the world. (Photo by Oli Scarff/Getty Images)

American soldiers leaping from an armoured personnel carrier during exercises in Korea, 17th March 1954. (Photo by Three Lions)