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)

Two animatronic velociraptors are on display during a technical rehearsal of “Walking with Dinosaurs The Live Experience” at the Indoor Stadium in Singapore, 29 August 2019. “Walking with Dinosaurs The Live Experience” is based on the BBC series of the same name and will run from 29 August to 08 September. (Photo by Wallace Woon/EPA/EFE/Rex Features/Shutterstock)

A man in a mock space suit experiences walking in space at “Mars Base 1 Camp” on May 15, 2023 in Jinchang, Gansu Province of China. The simulated Mars base allows visitors to immerse themselves in the Mars experience. (Photo by Li Yalong/China News Service/VCG via Getty Images)

Smoke rises from a replica of a T-Rex after it burst into flames at the Royal Gorge Dinosaur Experience in Canon City, Colorado, U.S. in this picture obtained from social media March 22, 2018. (Photo by Reuters/Royal Gorge Dinosaur Experience)

Ivy Levan is seen on the Universal Music Group stage at the SXSW 2015 Experience, Friday, March 20, 2015, in Austin, Texas. (Photo by Jack Dempsey/Invision for Universal Music Group/AP Images)

An authenticated contemporary copy of Leonardo da Vinci's Mona Lisa on display at the Prado Museum on February 1, 2012 in Madrid, Spain. Experts of the Prado Museum say the copy was painted at the same time as the Mona Lisa in Leonardo Da Vinci's studio by one of his students.

Ratana Das, 40, a female vendor, carries sacks full of clothes at a second-hand clothing market early morning in Kolkata, India, March 10, 2016. Das said she was born and brought up in Kolkata and feels proud being a resident of the city that gives her he opportunity to be financially independent. (Photo by Rupak De Chowdhuri/Reuters)

A hand reaches out to touch a dinosaur during the “Jurassic Quest” experience at Broward County Convention Center on July 08, 2022 in Fort Lauderdale, Florida. (Photo by Joe Raedle/Getty Images)