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)

A model presents a creation at the Moschino fashion show during Milan Fashion Week Spring/Summer 2017 in Milan, Italy, September 22, 2016. (Photo by Alessandro Garofalo/Reuters)

Dancers attend a photocall for the new “The One – Grand Show” at Friedrichstadt-Palast in Berlin, Germany September 28, 2016. The show, which features costumes by French fashion designer Jean Paul Gaultier, premieres on 06 October. (Photo by Hannibal Hanschke/Reuters)

A huge wave crashes against Castlerock pier as professional surfer Al Mennie waits on a break in the swell on December 22, 2016 in Coleraine, Northern Ireland. Storm Barbara is expected to cause major travel disruption when it hits northern parts of the UK later with 90mph winds predicted. The Met Office has issued an amber warning with the worst effects of the storm expected on Friday and Saturday. (Photo by Charles McQuillan/Getty Images)

A model presents a creation by Versace from the Spring/Summer 2023 collection during the Milan Fashion Week, in Milan, Italy, 23 September 2022. The Milano Fashion Week Women's runs from 20 to 26 September. (Photo by Mourad Balti Touati/EPA/EFE)

A groom leads his horse in the equine pool after working out on the track, during early morning workouts for the upcoming Derby race in Mumbai January 29, 2015. (Photo by Danish Siddiqui/Reuters)

Caporal dancers perform during the carnival celebrations in Oruro, Bolivia, Saturday February 14, 2015. The Carnival of Oruro which is a religious festival dating back more than 2000 years in an ongoing pagan-catholic blend of religious practice in the region, and is one of UNESCO's Masterpieces of the Oral and Intangible Heritage of Humanity. (Photo by Juan Karita/AP Photo)

Revelers throw colored corn starch into the air as they celebrate the 2015 Holi (Festival of Colors) at the Krishna Temple in Spanish Fork, Utah on Saturday, March 28, 2015. (Photo by Rick Bowmer/AP Photo)