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)

This photo released by the Cleveland Animal Protective League shows Lurleen, the nursing mother and Noland the puppy snuggling up Wednesday, June 19, 2013, in Cleveland. Lurleen already is caring for four newborn kittens and now is nursing the orphaned week-old pit bull puppy in Cleveland. (Photo by AP Photo/Cleveland Animal Protective League)

A bakery worker carries fresh bread in Cairo, Egypt on August 1, 2021. (Photo by Amr Abdallah Dalsh/Reuters)

Dinosaur mockups are installed in Danghangpo, Goseong, some 466km southeast of Seoul, South Korea, 06 September 2021, 25 days ahead of the Gyeongnam Goseong Dinosaur World Expo 2021 set for 01 October until 07 November. Goseong is one of the world's three largest fossilized dinosaur footprint sites, along with Colorado in the United States and the west coast of Argentina. (Photo by Yonhap/EPA/EFE)

A man cries over the body of his girlfriend, who was killed by shelling in the Kalininsky district of Donetsk, territory under control of the pro-Russian Government of the Donetsk People's Republic in eastern Ukraine, Thursday, June 9, 2022, during the Russian invasion. (Photo by Alexei Alexandrov/AP Photo)

Children play in the Crown Fountain at Millennium Park in Chicago, Wednesday, June 29, 2022. (Photo by Nam Y. Huh/AP Photo)

Mahsa Kadkhoda #11 of Team Iran spikes the ball during their semi-final round match against Team Chinese Taipei on day seven of the AVC Cup For Women at PhilSports Arena on August 28, 2022 in Pasig, Philippines. (Photo by Ezra Acayan/Getty Images)

England's full-back Freddie Steward dives across the line to score a try chased by Japan's wing Lomano Lemeki (L) during the France 2023 Rugby World Cup Pool D match between England and Japan at Stade de Nice in Nice, southern France on September 17, 2023. (Photo by Nicolas Tucat/AFP Photo)