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)

“The frilled shark (Chlamydoselachus anguineus) is one of two extant species of shark in the family Chlamydoselachidae, with a wide but patchy distribution in the Atlantic and Pacific Oceans. This uncommon species is found over the outer continental shelf and upper continental slope, generally near the bottom though there is evidence of substantial upward movements. It has been caught as deep as 1,570 m (5,150 ft), whereas in Suruga Bay, Japan it is most common at depths of 50–200 m (160–660 ft). Exhibiting several “primitive” features, the frilled shark has often been termed a «living fossil»”. – Wikipedia

Photo: A 1.6 meter long Frill shark swims in a tank after being found by a fisherman at a bay in Numazu, on January 21, 2007 in Numazu, Japan. The frill shark, also known as a Frilled shark usually lives in waters of a depth of 600 meters and so it is very rare that this shark is found alive at sea-level. It's body shape and the number of gill are similar to fossils of sharks which lived 350,000,000 years ago. (Photo by Awashima Marine Park/Getty Images)

Autos sit on top of each other in a washed out section of Dog Track Road in the Millview community as Gulf Coast residents continue cleaning up from damage caused by torrential rains in Pensacola, Fla., Thursday, May 1, 2014. The National Weather Service, estimated 15-20 inches of rain has fallen in the Pensacola area in the past 2 days. (Photo by G. M. Andrews/AP Photo)

A visitor poses behind the artwork “Convergence” by artist Masarrat Fatima M Sulaimani and curated by Samar Kamel at the World Art Dubai fair at the Dubai World Trade Centre in the Gulf Emirate of Dubai, United Arab Emirates, 08 October 2020. Around 2,000 art pieces are displaying at the sixth edition of the World Art Dubai fair which is running from 08 to 10 October 2020. (Photo by Ali Haider/EPA/EFE)