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)

Revellers dressed in mock military garb take part in the “Els Enfarinats” battle in the southeastern Spanish town of Ibi on December 28, 2017. During this 200-year-old traditional festival participants known as Els Enfarinats (those covered in flour) dress in military clothes and stage a mock coup d'etat as they battle using flour, eggs and firecrackers outside the town hall as part of the celebrations of the Day of the Innocents. (Photo by Jaime Reina/AFP Photo)

A US Marine leads two Viet Cong suspects in restraints during the Tet Offensive on February 20, 1967. (Photo by Bettmann Archive/Getty Images)

Police investigators inspect the bodies of two men lying on a sidewalk, who police said were killed after a drug “Shabu” (Methamphetamine Chloride) buy-bust operation in Quezon city, Metro Manila Philippines, October 9, 2016. (Photo by Ezra Acayan/Reuters)

A model walks the runway in the Maria Escote fashion show during the Mercedes-Benz Fashion Week Madrid Autumn/Winter 2012 at Ifema on February 4, 2012 in Madrid, Spain. (Photo by Carlos Alvarez/Getty Images)

Florida Division of Forestry fire fighter, Tim Abramczyk, sprays foam on a hotspot that flared up as he works on containing a 50,316-acre brush fire on June 10, 2011 in West Dade, Florida. The fire started last weekend as South Florida continues to endure a dry start to the rainy season and drought conditions have begun to appear. The forestry division has the fire about 55 percent contained. (Photo by Joe Raedle/Getty Images)

Indian soldiers practice their stunts on Royal Enfield motorcycles in preparation for the upcoming Republic Day parade on January 11, 2012 in New Delhi, India. (Photo by Daniel Berehulak /Getty Images)