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)

Zappa, a toothless 15-year-old Italian greyhound that looks surprisingly like Sid the Sloth from the animated movie Ice Age, is redefining dog beauty. Owners Sadie and Rosalie Millen, of Pewaukee, Wisconsin, say that Zappa started sticking her tongue out a few years ago when she lost her teeth.

Underwater photographer Alexander Semenovs has snapped some of the most stunning, fragile life forms anywhere on planet Earth. Shot in deep, dark conditions, the images continue to provide an insight into what lies beneath, with glowing creatures appearing a lot like aliens in the pitch-black water. Semenovs has shot the likes of bioluminescent jellyfish, aggressive-looking worms and many species that leave a lot to the imagination. The 30-year-old from Moscow does the majority of his work in the White Sea, near the Arctic Circle. Here: A Comb jelly – Beroe cucumis. (Photo by Alexander Semenovs/Caters News)

In the remote Argentine Pampas you can find an incredible forest formed in the shape of a guitar. More than 35 years ago, Pedro Ureta unexpectedly lost his wife to a brain aneurysm. Devastated by the loss of his love, he decided to create a shrine to her memory in their field that could only be seen above-head from an airplane. Ureta chose a guitar because it was his late wife’s most loved instrument.

Afghan children have ice cream during the Afghan New Year (Newroz) celebration in Kabul March 21, 2014. Afghanistan uses the Persian calendar which runs from the vernal equinox. The calendar takes as its start date the time when the Prophet Mohammad moved from Mecca to Medina in 621 AD. The current Persian year is 1393. (Photo by Ahmad Masood/Reuters)

Second World War veteran 90 year old William Walker launches the Scottish Poppy Appeal, together with soldiers from the Royal Highland Fusiliers, 2nd Battalion the Royal Regiment of Scotland, on October 27, 2011 in Penicuick, Scotland. Mr Walker, who was wounded while serving in Burma in 1943 with the Royal Scots, helped the soldiers form the shape of ninety to celebrate the 90th anniversary of the annual November campaign. (Photo by Jeff J Mitchell/Getty Images)

In this photo taken Sunday, May 6, 2012, Denis Lutskevich, left, is detained by police during an opposition rally in Bolotnaya Square in Moscow. The former naval cadet and first-year student, 21-year-old Lutskevich was attending his first protest when he was detained, and is still in prison Monday May 6, 2013, on the first year anniversary of the protest. (Photo by Pavel Golovkin/AP Photo)

Shemika Charles limbos under her car at Niagara Falls State Park on May 28, 2015 in Buffalo, New York. A world record holding limbo queen thinks she has become the first person to shimmy under a car. Shemika Charles amazed herself and onlookers when she bent over backwards to get underneath the SUV earlier this week. The supple 22-year-old entered the record books in 2010 when she limboed down to an incredible eight and a half inches – the height of a beer bottle. She trains for up to four hours a day to keep her body in peak condition and now travels around America performing with her family. However, regular performances put an incredible strain on her body and she sees a chiropractor once a week to have her hips realigned. Her mother was also a successful limbo dancer in her home country of Trinidad and Tobago but had to give up due to injury. (Photo by Ruaridh Connellan/Barcroft USA)