Buddhist monks take shelter under a tarpaulin sheet to protect themselves from the rain as they attend the birthday celebrations of the Tibetan spiritual leader the Dalai Lama (unseen) at Drepung Loseling Monastery in Mundgod, in the southern state of Karnataka, India, July 6, 2016. (Photo by Abhishek N. Chinnappa/Reuters)

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)

Heavy artillery on parade during a review of the Moscow Garrison troops during the May Day celebrations in Red Square, passing posters of Lenin and Stalin. (Photo by N. Sitnikov/Hulton Archive/Getty Images). 1st May 1947

A model presents a creation for Irish-American designer Paul Costelloe during the catwalk show for his Autumn/Winter 2023 collection on the opening day of the London Fashion Week, in London, on February 17, 2023. (Photo by Niklas Halle'n/AFP Photo)

Senator Barack Obama (D-IL) (R) stands in front of Senator Hillary Clinton (D-NY) as they arrive for U.S. President George W. Bush's annual State of the Union speech to a joint session of Congress at the U.S. Capitol in Washington in this January 23, 2007 file photo. Hillary Clinton announced her second run for the presidency on April 12, 2015 starting her campaign as the Democrats' best hope of fending off a crowded field of lesser-known Republican rivals and retaining the White House. (Photo by Larry Downing/Reuters)

Actress Liv Tyler poses for a portrait during the 2012 Sundance Film Festival at the Getty Images Portrait Studio at T-Mobile Village at the Lift on January 21, 2012 in Park City, Utah. (Photo by Larry Busacca/Getty Images)

Woman on swings attached to a float during the Sexual Freedom Parade, part of Naughty in N'awlins held in New Orleans, Louisiana, Wednesday July 5th, 2017. These are the photos from inside the world’s largest swinging convention for couples. The exclusive images reveal the unlikely couples who like to engage in sexual relations with other people besides their partners – and show that swinging is more ‘normal’ than you think. (Photo by Mathew Growcoot/News Dog Media)