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)

Three very colouful alpacas enjoy the hot weather at Toft Farm, Rugby, on July 19, 2013. (Photo by Caters News)

Motoring enthusiasts take part in the “Race The Wave” classic car meet on the beach at Bridlington, Britain on June 18, 2022. (Photo by Lee Smith/Reuters)

A man wades through flood waters carrying his grand daughter on his back following rains and floods during the monsoon season in Charsadda, Pakistan on August 28, 2022. (Photo by Fayaz AzizAziz/Reuters)

A fashion lovers walks in the courtyard of the Louvre museum during Louis Vuitton ready-to-wear Spring/Summer 2023 fashion collection presented Tuesday, October 4, 2022 in Paris. (Photo by Christophe Ena/AP Photo)

Zookeeper Agata holds a rare newborn Brazilian three-banded armadillo inside its enclosure at the Wroclaw Zoo in Wroclaw, Poland on May 11, 2023. The Tolypeutes matatus, or the southern armor also known as bolita or tatu-bola, is a fairly popular animal in South America but is increasingly rare. The new zoo child was born on March 23. The species is listed as vulnerable by the International Union for the Conservation of Nature (IUCN) and threatened by habitat loss and hunting. (Photo by Omar Marques/Anadolu Agency via Getty Images)

Mainland Chinese tourists run along a promenade during a typhoon in Hong Kong, Monday, July 17, 2023. Schools and the stock market were closed in Hong Kong on Monday as Typhoon Talim swept south of the city. (Photo by Louise Delmotte/AP Photo)

This photo provided by Red Antler Processing shows the alligator sport hunting team made up of, from left, Tanner White, tag-holder Donald Woods, Will Thomas and Joey Clark as they hoist, with the help of a forklift, the longest alligator officially harvested in Mississippi, Saturday, August 26, 2023, at Red Antler Processing in Yazoo City, Miss. The male alligator weighed 802.5 pounds and measured 14 feet, 3 inches long, and its length broke the state record as the longest alligator ever caught, according to the Mississippi Department of Wildlife, Fisheries and Parks. (Phoot by Shane Smith/Red Antler Processing via AP Photo)