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)

One of three young oriental small-clawed otters eats a meatball on June 18, 2015 in a zoo in Dresden, eastern Germany. The oriental small-clawed otter female Fussi gave birth to 3 healthy pups. Its pups now leave their burrow to explore the environment. (Photo by Arno Burgi/AFP Photo/DPA)

Chippi, 22, from Senegal sits on someone’s shoulder shirtless participating in a large snow ball fight in Washington Square Park on January 29, 2022 in New York City. According to the National Weather Service New York City is expected to receive between 8-12 inches of snow and 40 to 45 mph wind gusts during the first major Nor’Easter storm of the season. New York City Mayor Eric Adams announced that there is a 24 hour a State of Emergency in effect. (Photo by Alexi Rosenfeld/Getty Images)

A young fan watches as Green Bay Packers running back AJ Dillon (28) tries his best to ride her bicycle to training camp on Monday, August 1, 2022, at Ray Nitschke Field in Green Bay, Wis. (Photo by Dan Powers/USA TODAY Sports)

A small meadow pipit (left) is run off her feet as she tries to keep up with the demanding feeding schedule of an imposter - a larger cuckoo (right) on the Isle of Mull, Scotland in August 2022. (Photo by Graeme Cuerden/Solent News & Photo Agency)

Argentine Spanish model Georgina Rodriguez arrives on September 1, 2022 for the screening of the film “Tar” presented in the Venezia 79 competition at the 79th Venice International Film Festival at Lido di Venezia in Venice, Italy. (Photo by Guglielmo Mangiapane/Reuters)

A dog sits in a plastic tub filled with water in Taipei, Taiwan, 28 July 2020. Betel nut seller Mr Luo, the dog's owner, said he puts his dog, a 12-year-old mixed breed called Ah Dai (Stupid), in a plastic tub filled with water whenever the weather gets hot. Ah Dai enjoys the bath and can sit in the basin for hours, according to Mr Luo. Luo has a dozen pairs of glasses for Ah Dai, so the dog wears different glasses every day and many tourists take photos of Ah Dai. (Photo by David Chang/EPA/EFE)

Social distancing signs are pictured as models wear protective face masks before the show of designer Andres Sarda during the Mercedes Benz Fashion Week amid the coronavirus disease (COVID-19) outbreak in Madrid, Spain, September 10, 2020. (Photo by Sergio Perez/Reuters)