A monarch butterfly rests on the ground at the Sierra Chincua butterfly sanctuary on a mountain in Angangeo, Michoacan November 24, 2016. Angangueo is a town and municipality located in far eastern Michoacán state in central Mexico noted for its history of mining and its location in the Monarch Butterfly Biosphere Reserve. The Monarch Butterfly Biosphere Reserve is a World Heritage Site containing most of the over-wintering sites of the eastern population of the monarch butterfly. (Photo by Carlos Jasso/Reuters)

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)

New York City Mayor Michael Bloomberg gets on a custom made World Trade Center inspired motorcycle in front of the 9/11 Memorial Preview Site on October 5, 2011 in New York City. The motorcycle was designed by Paul Teutul Jr. of the television show “American Chopper” and was built to commemorate the rebuilding of the World Trade Center Site. Another motorcycle, nearly identical to the one unveiled, will also be built by Paul Jr. and raffled to raise money for the 9/11 Memorial. (Photo by Spencer Platt/Getty Images)

From sandwich-saurus to a scary leprechaun the sometimes terrifying and often hilarious foodstuffs are the creation of New York artist Kasia Haupt. The 29-year-old advertising art director has even had her work commissioned as prints making her a real-life Salvador DELI. Photo: “Kasia Haupt's sandwich monsters: Love Bunnies”. (Photo by Kasia Haupt/Caters News)

Photographer Frank Relle takes long-exposure images of houses in New Orleans. Says Relle, “The city at night comes alive for me. I imagine stories about the people’s lives inside the homes based on the evidence on the outside. My photographs become a portrait without the person. The night obscures details and the lack of information gives possibility”. Photo: “Telemachus”. Farragut Street, New Orleans, La. Nov. 2006. (Photo by Frank Relle)

“These dolly birds are showing off the latest haute COO-ture in a stunning set of images that portray everyday pigeons as fashion models. The series, titled “Darwin’s Pigeons”, was snapped by British photographer Richard Bailey, who was looking to capture the birds’ photogenic side as a tribute to the Father of Evolution himself, who it is believed was fascinated by the birds”. – Caters News. Photo: Old Dutch Capucine. Darwin’s Pigeons series. (Photo by Photo by Richard Bailey/Caters News)

Participants take part in the annual New Year' s Day Parade in central London, United Kingdom on January 1, 2018. Reports state that 8,000 performers representing the London boroughs and countries from across the globe are parading along the streets of London's West End on New Year’s Day. (Photo by Tolga Akmen/AFP Photo)

Revelers celebrate during fireworks marking the start of the New Year on Copacabana beach on January 1, 2017 in Rio de Janeiro, Brazil. Brazilian revelers traditionally dress in white to honor the New Year's holiday along with the Brazilian Goddess of the Sea- Iemanja. (Photo by Mario Tama/Getty Images)