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)

Photographers wear clothing with cooling fans and staff members wear cloths that protects them from the sun as they prepare for fashion photo session on a street, amid a heatwave warning in Shanghai, China on July 25, 2022. (Photo by Aly Song/Reuters)

White horses of the Camargue thunder through the shallow salt flats at sunset on December 8, 2022. Known as Horses of the Sea, the breed native to the wetlands in southern France is one of the oldest in the world. (Photo by Nathalie Mountain/Media Drum Images)

Friends (L-R) Katherine Olson, Olivia Carroll and Maron Ross take a memory during the 148th running of the Preakness Stakes at Pimlico Race Course on May 20, 2023. (Photo by Jonathan Newton/The Washington Post)

Macaque monkeys sit on a car in Hua Hin on May 29, 2020, as low tourist numbers due to the ongoing COVID-19 novel coronavirus situation have resulted in a decrease in the number of people feeding them. The monkeys in the town are going hungry as a consequence of the drop in tourism as a result of the COVID-19 coronavirus pandemic. (Photo by Jack Taylor/AFP Photo)

Kindergartner Cameron McManus, 5, watches as a fellow student has his portrait made during “picture day” at Rogers International School on September 23, 2020 in Stamford, Connecticut. Students lined up outside to be photographed while socially distanced due to COVID-19 precautions. Most students at Stamford Public Schools are taking part in a hybrid education model, attending in-school classes every other day and distance learning the rest. (Photo by John Moore/Getty Images)

Gentoo penguins watching Christmas films at the Sea Life London aquarium on November 30, 2020. The attraction has installed two TVs, showing festive films, outside the penguin enclosure to prepare them for the stimulation of guests returning on Wednesday after the UK’s lockdown is lifted. (Photo by Yui Mok/PA Images via Getty Images)

Tribal artists and supporters from the southern Indian state of Karnataka dance outside the residence of Congress Party President Sonia Gandhi during her birthday celebrations in New Delhi, India, Wednesday, December 9, 2015. The Italian-born Gandhi is the widow of former Prime Minister Rajiv Gandhi and has led the Congress party since 1998. (Photo by Altaf Qadri/AP Photo)