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)

A man sits next to a damaged idol of Hindu goddess Kali which was taken out after its immersion in the river Ganges in Haridwar, India, March 29, 2017. (Photo by Danish Siddiqui/Reuters)

A couple takes a selfie as Hoa Binh hydroelectric power plant opens the flood gates after a heavy rainfall caused by Talas typhoon in Hoa Binh province, outside Hanoi, Vietnam July 20, 2017. (Photo by Reuters/Kham)

People protest at the Boston Free Speech Rally in Boston, USA on August 19. 2017. With the Boston Free Speech rally was closed to the media (despite the Boston Common being a public space), a lot of the media’s coverage centred on the tensions within the larger counter-protest. (Photo by Stephanie Keith/Reuters)

Residents recently returning to their area cleared by government troops react as they ride a tricycle a day after President Rodrigo Duterte declared the liberation of Marawi city in southern Philippines Wednesday, October 18, 2017. Sporadic explosions continue Wednesday as Philippine soldiers fought to gain control of the last pocket of Marawi controlled by Islamic militants. (Photo by Bullit Marquez/AP Photo)

People react as a Canadian man wearing only a pair of shorts orders a drink from a fast food outlet in Gangneung Curling Centre on day 10 of the PyeongChang 2018 Winter Olympic Games on February 19, 2018 in Gangneung, South Korea. (Photo by Carl Court/Getty Images)

Women dancing at the disco club Xenon in New York City, USA in 1978. Xenon was a popular disco in Manhattan in the late 1970s and early 1980s. It was the only nightclub popular enough to compete with Studio 54. (Photo by Waring Abbott/Getty Images)

A man hugs a child at the Santuario de Nuestra Senora de Guadalupe during a celebration on the Virgin of Guadalupe Day in Guatemala City, December 12, 2015. According to Catholic believers, December 12 marks the anniversary of the apparition of the Virgin of Guadalupe at the Cerro del Tepeyac in Mexico. (Photo by Jorge Dan Lopez/Reuters)