A cat wearing a dress is carried around in a transparent rucksack at the annual Pet Expo Thailand 2021 in Bangkok on November 25, 2021. (Photo by Jack Taylor/AFP Photo)

Postal worker Eddie Smith, dressed as Santa Claus, waves to a neighbor on his mail route in Washington, U.S., December 21, 2021. (Photo by Evelyn Hockstein/Reuters)

Goose, a nine-month-old cat, sits in a backpack as people gather during a Speak Out Against Sexual Violence demonstration at Eastern Michigan University in Ypsilanti, Michigan, U.S., March 28, 2021. (Photo by Emily Elconin/Reuters)

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 staff member demonstrates how she puts on the helmet of a mock space suit at the C-Space Project Mars simulation base in the Gobi Desert outside Jinchang, Gansu Province, China, April 17, 2019. The facility – comprising several interconnected modules including a greenhouse and a mock decompression chamber – opened its doors to the public. (Photo by Thomas Peter/Reuters)

Members of Team Japan compete in the Artistic Swimming Team Acrobatic Final on day four of the Fukuoka 2023 World Aquatics Championships at Marine Messe Fukuoka Hall A on July 17, 2023 in Fukuoka, Japan. (Photo by Quinn Rooney/Getty Images)

Young siblings in costume fully embrace the Notting Hill carnival atmosphere in London, England on August 28, 2023. (Photo by Nico Froehlich/The Guardian)

An elephant with a shackled leg is pictured at the Hanoi Zoo in Hanoi on August 16, 2023. Legs in iron chains and unable to roam freely, the treatment of two elderly elephants at the Hanoi public zoo has drawn outrage from animal lovers across Vietnam. (Photo by Nhac Nguyen/AFP Photo)