In the spring of 1965, within weeks of 3,500 American Marines arriving in Vietnam, a 39-year-old Briton named Larry Burrows began work on a feature for LIFE magazine, chronicling the day-to-day experience of U.S. troops on the ground – and in the air – in the midst of the rapidly widening war. The photographs in this gallery focus on a calamitous March 31, 1965, helicopter mission; Burrows’ “report from Da Nang”, featuring his pictures and his personal account of the harrowing operation, was published two weeks later as a now-famous cover story in the April 16, 1965, issue of LIFE.

Photo: Man your battle stations: The crew chief of helicopter Yankee Papa 13, lance corporal James C. Farley, mans an M-60 machine gun during a mission near Da Nang, Vietnam on March 31, 1965. (Photo by Larry Burrows/Time & Life Pictures)

Russian opposition leader, Alexei Navalny (C), reacts as the court delivers the verdict in his trial, in the city of Kirov, Russia, 18 July 2013. Alexei Navalny was sentenced to five years in jail for theft on Thursday, an unexpectedly tough punishment which supporters said proved President Vladimir Putin was a dictator ruling by repression. (Photo by Valentina Svistunova/EPA)

A photographer tested the concentration of several pairs of dogs as he captured their reactions to treat time in a series of shots. Christian Vieler, 47, of Waltrop, Germany, has been a professional dog photographer since 2016. He came up with the idea of snapping two dogs catching treats simultaneously. Here: Basset Hounds. (Photo by Vieler Photography/Caters News Agency)

Australian model Kate Fischer (Tziporah Malkah) poses with a Cointreau Ball to celebrate France’s founding anniversary in Sydney, Australia on July 14, 1996. (Photo by Getty Images)

A Brussels Airlines aircraft prepares for landing in Cointrin airport during sunrise over the Mont Blanc in Geneva December 1, 2011. (Photo by Denis Balibouse/Reuters)

A bloodied man who carried dead and wounded, speaks on the phone at the site of a suicide attack an explosion that struck a protest march, in Kabul, Afghanistan, Saturday, July 23, 2016. Witnesses in Kabul say that an explosion causing multiple casualties struck the march by members of Afghanistan’s largely Shiite Hazara ethnic minority group, who were demanding that a major regional electric power line be routed through their impoverished home province. (Photo by Omar Sobhani/Reuters)

In northwest Russia, in a small village called Alekhovshchina, Nadia Sablin's aunts spend the warmer months together in the family home and live as the family has always lived, chopping wood to heat the house and making their own clothes. Sablin's book of photographs, “Aunties: The Seven Summers of Alevtina and Ludmila”, is published by Duke University Press. Here: “Two-Handed Saw, 2014”. (Photo by Nadia Sablin)

American Ballet Theater's dancers are silhouetted as they rehearse for the opening night at the Shanghai Grand Theater in Shanghai, Thursday, November 2, 2023. The American national ballet company is returning to China for the first time in a decade for shows in Shanghai and Beijing in the latest sign strained relations between the United States and China are beginning to thaw. (Photo by Ng Han Guan/AP Photo)