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)

Principal of the Royal Ballet, Natalia Osipova, performs outside the Edinburgh International Conference Centre in Edinburgh, England on November 21, 2018, where she is starring in the new contemporary ballet “The Mother”. (PHoto by Jane Barlow/PA Wire via ZUMA Press)

Monkeys climb onto tourists during the annual Monkey Festival in Lopburi province, Thailand on November 26, 2023. (Photo by Chalinee Thirasupa/Reuters)

Seen in a long exposure nighttime photograph, a burned van rests in a lot while a wildfire glows on the horizon in Phelan, Calif., early Thursday, August 18, 2016 2016. (Photo by Noah Berger/AP Photo)

An internally displaced Afghan girl holds a child at a refugee camp in Kabul, Afghanistan May 31, 2016. (Photo by Mohammad Ismail/Reuters)

A demonstration on March 15, 1922 on Palace Roof, 57th Street and 7th Avenue, showing the shellproof steel jacket. Leo Krause wearing the jacket, which weighs 12 pounds. Shots used, 38 and 45 calibre, at close range. (Photo by Bettmann Archive)

Sailors pause to take a photo with characters in Times Square during “Fleet Week 2024” in New York City on May 22, 2024. (Photo by Caitlin Ochs/Reuters)

Guests arrive for the Arlo Guthrie concert at the Bethel Woods Center for the Arts, the original site of the Woodstock Festival, on the 50th anniversary in Bethel, New York, U.S. August 15, 2019. (Photo by Brendan McDermid/Reuters)