Senator Barack Obama (D-IL) (R) stands in front of Senator Hillary Clinton (D-NY) as they arrive for U.S. President George W. Bush's annual State of the Union speech to a joint session of Congress at the U.S. Capitol in Washington in this January 23, 2007 file photo. Hillary Clinton announced her second run for the presidency on April 12, 2015 starting her campaign as the Democrats' best hope of fending off a crowded field of lesser-known Republican rivals and retaining the White House. (Photo by Larry Downing/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)

Children beg for alms in a street on August 11, 2014 in Manila, Philippines. The Philippines has one of the fastest growing populations in Southeast Asia with around 100 million people. At least 12 million people live in the capital city of Manila alone, making it one of the most densely populated and largest cities in the world. Lack of space and economic opportunities has pushed around four million people to live informally along waterways, bridges and even cemeteries further straining the already weak infrastructure and straining the resources of the city. (Photo by Dondi Tawatao/Getty Images)

An open water swimmer surfaces as she enjoys a socially-distanced dawn swim after breaking the ice on the surface of a lake near Scunthorpe, northern England, January 9, 2021. Faced by a sharp rise in coronavirus infections, driven by the new strain, England entered a strict lockdown on January 5, 2021, with schools and non-essential shops closed for at least six weeks after previous measures failed to halt the steep rise in cases. (Photo by Lindsey Parnaby/AFP Photo)

Real life doll Alina Kovalevskaya poses for a photograph on May 29, 2014 in Odessa, Ukraine. Alina Kovalevskaya is a walking, talking, breathing living doll on the lookout for her real-life Ken. The 21-year-old is from Odessa, Ukraine – the same city as real-life Barbie Valeria Lukyanova, who has made headlines around the world for her unique look and controversial opinions. The pair were friends, but their relationship has since soured. Alina has made a splash online, with her YouTube videos showing off her doll-like charms attracting hundreds of thousands of views. (Photo by Aleksey Solodunov/Barcroft Media)

An Afghan girl carries water on her back as she climbs a hill in Kabul, Afghanistan February 20, 2017. A growing population is straining water supplies in Afghanistan's capital, forcing those who can afford it to dig unregulated wells ever deeper to tap a falling water table. Finding water in arid Afghanistan is virtually always a challenge, but a drop in the groundwater level in Kabul caused by overuse and drought is making it even more difficult for residents, especially the poor. (Photo by Omar Sobhani/Reuters)

In this May 21, 2021, file photo, JoJo Hamner, a cast member of the “Sexxy After Dark: Where Dinner Meets Play” show, gets the Pfizer COVID-19 vaccine during a pop-up vaccine clinic at Larry Flynt's Hustler Club in Las Vegas. It's one of several methods health officials are employing here and across the country to bring vaccines directly to people to counter waning demand. In tiny towns, ballparks, strip clubs, and marijuana dispensaries, officials are setting up shop and offering incentives to entice people who so far have not gotten shots. (Photo by Ellen Schmidt/Las Vegas Review-Journal via AP Photo/File)

In this February 7, 2014 file photo, Matt Figi hugs and tickles his once severely-ill seven year old daughter Charlotte, as they walk together inside a greenhouse for a special strain of medical marijuana known as Charlotte's Web, which was named after the girl early in her treatment for crippling severe epilepsy, in the mountains west of Colorado Springs, Colo. Colorado is poised to award more than $8 million for medical marijuana research, a step toward addressing complaints that little is known about pot's medical potential. Among the research projects poised for approval on Wednesday, December 17, 2014, are one for pediatric epilepsy patients, and another for children with brain tumors. (Photo by Brennan Linsley/AP Photo)