Vernon and Irene Castle had reached the peak of their fame in 1914.
The husband-and-wife dance team starred in Irving Berlin's first Broadway show, Watch Your Step. They helped popularize the Fox-trot as well as ragtime, jazz rhythms, and African American music for dance.
But Vernon gave up stage and stardom to fly combat missions during World War I - a decision that led to his death in a plane crash in 1918.
D. Willard Zahn of Philadelphia was there and captured the wreckage in one of 57 black-and-white pictures he assembled in an album later passed on to his son, Dick, of Pitman, Gloucester County.
As the First World War's centennial is marked this July, the rare, haunting images of pilot training open a window on a bygone time when fixed-wing flight was still new and many military cadets were killed learning to fly rickety biplanes.
One picture shows an obviously dejected pilot leaning against a wing as others step through a cotton field to inspect the plane he had just crash-landed.
In others, a flier stands with a bandaged hand and face next to another smashed aircraft; a wrecked biplane marks the spot where a pilot died; and cadets sit on bunks and trunks in spartan Texas barracks, their flight suits hung nearby.
"These guys in World War I were the astronauts of their day," said Dick Zahn, 85, a professor of psychology who retired about 20 years ago from what was then Glassboro State College. "They were pioneers who took their lives in their hands."
Zahn treasured his late father's album and shared it over the winter with John Leach, vice chairman of the Pitman Memorabilia Committee, which seeks to preserve the community's history.
"I think flying was my father's great adventure," said Zahn, a Navy veteran who served in the United States at the end of World War II, and was briefly stationed in Kwajalein in the Marshall Islands and near Manila in the Philippines during the Korean War. "I guess he wanted a record of his military service, but he was very, very modest and never talked about it."
Leach was surprised to see the photos and scanned them onto a DVD for Zahn. He also checked with the National World War I Museum in Kansas City, Mo., to learn more.
The images "documented an era 100 years old, from the ground school to the flight school," said Leach, a former New Jersey state trooper and civilian pilot who also lives in Pitman. "It's a real find. Where else would you find anything like this?"
Numerous World War I pictures have survived, but Zahn's clear images from flight training exercises in Texas are uncommon as a personal, never-before-seen history of a pilot's experience.
"They're evidence of what we're trying to preserve," said Doug Lantry, curator of the National Museum of the U.S. Air Force at Wright-Patterson Air Force Base in Ohio. "The tools, context, and surroundings [in photos] can often tell us things left out of documentary sources.
"Bottom line - this is a valuable visual record," he said. "A good set of undamaged prints from that era is an exciting thing."
D. Willard Zahn completed his preflight training at Princeton University before heading to Carruthers Field near Fort Worth, Texas. His photos reflect his whole training experience.
But Army Second Lt. Zahn never found himself in combat. The war ended Nov. 11, 1918, and he returned to Philadelphia, where he worked as a grade school physical education teacher, an elementary school principal, associate superintendent of schools and Temple University's dean of the College of Education.
"I had a feeling he never looked back at that album," said Dick Zahn. "He lived in the present and never volunteered much about his training.
But over time, the younger Zahn learned more about his father's experience from reading histories.
"Think about it," he said. "The Wright brothers had just flown [a power-driven, heavier-than-air machine] for the first time in 1903 and my father is flying in 1918.
"They didn't know how to pull out of spins back then," he said. With so many deaths, "the odds against you were pretty bad."
Beating the odds seemed easy for Vernon Castle, the ballroom dancer, who started flying for the Royal Flying Corps during World War I. He completed 300 combat missions over the Western Front, shot down two aircraft, and was awarded the Croix de Guerre.
In 1918, Castle was assigned to training American pilots and was taking off with a student on Feb. 15 when his plane stalled as he tried to avoid another aircraft. He wasn't able to recover and crashed. Apparently, his pet monkey had been along for the ride.
"Neither the other pilot, his student cadet, nor Vernon's pet monkey, Jeffrey, were seriously injured," according to a monument at the crash site.
D. Willard Zahn grabbed his camera and took a photo of the wreckage.
"My father must have known him," said Dick Zahn. "It must have been terribly sad."
Castle "was a celebrity, a great dancer, a guy with all these hundreds of hours in the air," he said. "How could it happen?"
The early pilots of that time "were doing something dangerous, new and exciting," said Lantry. "And that's why a lot of them wanted to do it."