Medic James E. Callahan of Pittsfield, Mass., gives mouth-to-mouth resuscitation to a dying soldier in war zone D, about 50 miles northeast of Saigon, June 17, 1967. Thirty-one men of the 1st Infantry Division were reported killed in the guerrilla ambush, with more than 100 wounded. (Photo by Henri Huet/AP Photo)

Passengers travel in an overcrowded train in the eastern Indian city of Patna, February 23, 2010. (Photo by Krishna Murari Kishan/Reuters)

A woman, wearing a traditional Sevillana dress, performs as she asks for alms in downtown Malaga, Spain, April 28, 2016. (Photo by Jon Nazca/Reuters)

Brides display their hands decorated with henna around a bride as she poses for her own photographer during a mass marriage ceremony in which, according to its organizers, 70 Muslim couples took their wedding vows, in Ahmedabad, India, February 11, 2018. (Photo by Amit Dave/Reuters)

A hippopotamus performs during a show at the circus in Krasnoyarsk, Siberia, Russia, July 7, 2016. (Photo by Ilya Naymushin/Reuters)

A woman carries her child in a basket as she walks on a road in Allahabad, India, August 11, 2016. (Photo by Jitendra Prakash/Reuters)

A traffic police officer directs vehicles at a street junction during sunset in Pyongyang, North Korea, Thursday, August 25, 2016. (Photo by Dita Alangkara/AP Photo)

An Indian artists uses sparkles to decorate statues of the Hindu god Lord Ganesh ahead of the forthcoming Ganesh Chaturthi festival at a workshop in Hyderabad on August 29, 2016. The statues are being prepared for the Ganesh Chaturthi festival a popular eleven-day long Hindu religious festival in India which will be celebrated from September 5 to 15. (Photo by Noah Seelam/AFP Photo)