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 ladyboy sеx worker wears a belt with a dollar sign on it while holding condoms and lube handed to her by Sisters, a transgendered outreach and community services organization in Pattaya, Thailand on August 25, 2016. Many of Thailand's ladyboys live in Pattaya, a large percentage of whom work in the sеx industry there. (Photo by Aaron Joel Santos/Getty Images/Aurora Creative)

A female Kurdistan Workers Party (PKK) fighter works on her laptop while watching a Kurdish TV station at a base in the Sinjar mountains, March 11, 2015. Women fighters at a Kurdistan Workers Party (PKK) base on Mount Sinjar in northwest Iraq, just like their male counterparts, have to be ready for action at any time. Smoke from the front line, marking their battle against Islamic State, which launched an assault on northern Iraq last summer, is visible from the base. Many of the women have cut links with their families back home; the fighters come from all corners of the Kurdish region. (Photo by Asmaa Waguih/Reuters)

Agricultural workers are rice-transplanting at the Namsa Co-op Farm of Rangnang District in Pyongyang, DPRK, on Tuesday, May 25, 2021. (Photo by Jon Chol Jin/AP Photo)

English actor Eddie Redmayne poses with fans at the premiere of “The Good Nurse” & Golden Eye Award for Eddie Redmayne during the 18th Zurich Film Festival at Kongresshaus on September 25, 2022 in Zurich, Switzerland. (Photo by Thomas Lohnes/Getty Images for ZFF)

B-boy Amin Drillz of Austria (front) competes during the 2022 World Breaking Championship at the Olympic Park in Seoul on October 21, 2022. (Photo by Anthony Wallace/AFP Photo)

Alexia Putellas of FC Barcelona celebrates victory with fans following the UEFA Women's Champions League Quarter Final Second Leg match between FC Barcelona and Real Madrid at Camp Nou on March 30, 2022 in Barcelona, Spain. (Photo by Alex Caparros – UEFA/UEFA via Getty Images)

Accordion player and broadcaster Gary Innes performing with dancer Rachel McLagan at The Ovo Hydro, Glasgow on Tuesday, April 5, 2022, to help launch, Hoolie in the Hydro, the World's Biggest Ceilidh, which will take place this December. (Photo by Andrew Milligan/PA Images via Getty Images)