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 lioness bares its teeth inside an enclosure after a raid at a zoo-like house on the outskirts of Bangkok, Thailand Monday, June 10, 2013. Thai police and forestry officials searched and seized a number of imported and endangered animals including 14 lions from Africa and arrested the house's owner. (Photo by Apichart Weerawong/AP Photo)

Hailey Hanestad thinks nothing about nuzzling up to the animal, called Wiley, and even dozes off with him on her bed. Wiley has been a treasured member of the family since being rescued by Hailey's dad, Rick, three years ago. Today he's thought to be just one of two coyotes in the US that have become domesticated after being born in the wild. Photo: Coyote Wiley sniffs Hailey, 8, at their home. (Photo by Barcroft Media)

A woman holds her dog as it is blessed by a priest in Benalmadena, near Malaga, Spain, January 17, 2016. Hundreds of pet owners bring their animals to be blessed every year on the day of San Anton, Spain's patron saint of animals. (Photo by Jon Nazca/Reuters)

“Like most Brits, Emmie Stevens is dog mad. But the 25-year-old has taken it to the next level, spending £30,000 on her nine pets. Emmie’s dogs enjoy regular manicures and fur dyes and have their own walk in wardrobe to store their £15,000 clothing collection”. – Daily Record. Photo: Bailey the Staffordshire bull terrier, holding a red rose. (Photo by Helen Yates/Barcroft Media)

Sage Colina holds Rhianna as she is prepared to be adopted from the Humane Society of Greater Miami on December 13, 2023 in Miami, Florida. The shelter is experiencing an overcrowding crisis, like many nationwide, with people releasing their family pets to animal shelters since they can no longer afford to take care of them, after the high cost of pet care and the expense of veterinarian services, among other reasons. (Photo by Joe Raedle/Getty Images)

Pet dogs wearing sunglasses and face mask on board a tricycle are pictured in Chinatown district of Manila on January 20, 2023, ahead of the Lunar New Year of the Rabbit which falls on January 22. (Photo by Ted Aljibe/AFP Photo)

Cheng Chen (R), a 27-year-old worker at a state-owned enterprise, poses for a photograph with his nephew who is wearing his home-made Iron Man armour, in Xuzhou, Jiangsu province April 13, 2015. It cost Cheng about 500 yuan ($81 USD) to make the armour, which weighs about 4 kilograms, with plastic boards and LED lights, local media reported. (Photo by Reuters/Stringer)