Kumbuka, a male silverback gorilla sits next to the keeper's chalk board in his enclosure at London Zoo, Thursday, January 2, 2014. Home to more than 850 different species, zoo keepers welcomed in the New Year armed with clipboards as they made a note of every single animal. The compulsory annual count is required as part of ZSL London Zoo's zoo license, and every creature, from the tiny leaf cutter ants to the huge silverback gorilla is duly noted and accounted for. (Photo by Kirsty Wigglesworth/AP Photo)

Wally Collins holds a bust of author Ernest Hemingway after winning the 2014 “Papa” Hemingway Look-Alike Contest in this handout photo provided by the Florida Keys News Bureau at Sloppy Joe's Bar in Key West, Florida July 19, 2014. Collins, a Phoenix resident, won the title on his sixth try during the event that was the highlight of Key West's annual Hemingway Days festival. (Photo by Andy Newman/Reuters/Florida Keys News Bureau)

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)

Handout photo dated March 20, 2015 issued by Chester Zoo of lemurs looking at the eclipse over Chester Zoo. (Photo by Steve Rawlins/PA Wire/Chester Zoo)

People enjoying the races on a wet day at Chester Racecourse on May 12, 2017 in Chester, England. (Photo by Alan Crowhurst/Getty Images)

Chester Zoo in the second decade of August 2025 has welcomed a pair of tiny golden lion tamarins, named George, seven, and Leaf, 12. (Phoot by Chester Zoo)

Solo, a rare baby tapir, makes his debut at Chester zoo, UK on July 18, 2016. The Malayan tapir is an endangered species and Solo is the first ever calf born at the zoo. (Photo by Chester Zoo/Rex Features/Shutterstock)

A baby otter has its first health checkup at Chester zoo, England on May 2, 2018. It was among five pups being weighed and microchipped. (Photo by Peter Byrne/PA Wire)