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 woman dressed up as a zombie takes part in a zombie walk in the Gaslamp Quarter during the Comic Con International convention in San Diego, California July 13, 2012. (Photo by Mario Anzuoni/Reuters)

Participants take part in a high-heel race at a Gay Pride party in the central neighborhood of Chueca in Madrid on July 3, 2014. (Photo by Gerard Julien/AFP Photo)

Grand prize winner: environmental photographer of the year 2023; also 1st place in the humanity v nature category; and winner of the 2023 public award. Lopé national park, Gabon, 2021. An angry elephant tries to defend itself after it was hit by a train that crosses paths the animals use within Lopé national park. Park officials decided the elephant was too severely injured to be saved. After it was killed, the park director distributed the meat to local people. As the forest loses its carrying capacity to sustain its megafauna, this kind of human-wildlife conflict is increasing. (Photo by Jasper Doest/Environmental Photography Award)

Elders perform coronation rituals on Kabaka (King) Ronald Muwenda Mutebi II during his 30 year coronation at his palace in Mengo, Kampala, on July 31, 2023. Thousands of Ugandans thronged the palace grounds of the country's largest kingdom Buganda despite pouring rain on July 31, 2023, dancing and ululating as they marked 30 years since the coronation of King Ronald Muwenda Mutebi II. (Photo by Badru Katumba/AFP Photo)

Models wear creations as part of the Dolce & Gabbana women's Spring Summer 2023 collection presented in Milan, Italy, Saturday, September 24, 2022. (Photo by Antonio Calanni/AP Photo)

A destroyed tank sits by the side of a road leading to Abi Adi, in the Tigray region of northern Ethiopia, on Tuesday, May 11, 2021. The Tigray People’s Liberation Front was on top of a coalition that ruled Ethiopia for nearly three decades. That changed in 2018, when Prime Minister Abiy Ahmed rose to power as a reformist. Abiy alienated the TPLF with efforts to make peace with its archenemy, Eritrea, and rid the federal government of corruption. (Photo by Ben Curtis/AP Photo)

An asylum-seeking migrant child from Honduras reacts as disembarking an inflatable raft after crossing the Rio Grande river into the United States from Mexico in Roma, Texas, U.S., June 8, 2021. (Photo by Go Nakamura/Reuters)