September 1, 2010It sounds utterly impossible: A New York City man jumps 39 stories from the roof of an Upper West Side apartment building, slams into a parked car and survives."Miracle!" proclaims the New York Daily News.On Tuesday morning, Thomas Magill, 22, plunged from a West 63rd Street apartment building and crashed into the backseat and trunk of a red Dodge Charger. The impact of the 490 foot drop was so great that Magill's Keds sneakers flew off his feet."My leg! My leg!" he reportedly screamed and was taken to St. Luke's hospital where he was upgraded Wednesday to critical condition after surgery to stop massive internal bleeding and repair his crushed legs. His motive for jumping remains unknown."He had his hands up in the air, like flailing," witness Andrew Petrocelli told the Daily News. "Just when he's about to land, there was a boom and glass flying all over," he added. "The car saved his life. He landed in there like a stunt man. It was amazing."Magill was upgraded to stable condition Wednesday at St. Luke's Hospital.Magill's story may sound like one in a million but it's not especially surprising if you delve into the obscure world of free falling. It turns out that people tumble from great heights all the time and survive... and their chances of survival actually improve if they're drunk, on drugs, suicidal or crazy, according to top experts in the field. Other key survival factors include landing position (Magill hit feet first; head first would have meant instant death) and the cushion or give of the impact surface. (If you're lucky enough to have a choice where you hit, snow happens to be a good landing pad for free-falling.)Dr. Richard Snyder knows more than anyone in the world about free falling and "human impact tolerances," the technical phrase for how much the body can withstand. Over a fifty-year career, he has researched more than thirty-three thousand falls of every height and variety.As a crash injury expert at the FAA in 1963, Snyder published a classic study of 137 falls, including a sixty-nine year-old woman who toppled from a tree while chasing her pet parakeet and an eloper who tumbled from a tall ladder. Snyder's subjects ranged in age from eighteen months to ninety-one years old. Humans, he concluded, are able to survive impact forces "considerably greater than those previously believed tolerable."Snyder retired to Tucson, Arizona, after careers in government, academia, and the private sector. When I interviewed him for my book The Survivors Club, he recalled gathering information on more than a thousand people who survived falls greater than a thousand feet -- more than twice the distance that Magill plunged on Tuesday."It isn't that unusual," he says matter-of-factly. It all depends on how you fall, where you land, and your own physical condition. Snyder's early research found that "psychotic patients," like suicidal people, may be able to withstand impact forces better than "normal" individuals. A crazy person who wants to leap from a building, he theorized, may be looser on the way down. "The act of jumping may thus be a release for him," he writes, "and unlike most of us, this individual may enjoy the jump. As a result he may be physically relaxed at the time of impact, which appears to be, in itself an important criterion for survival of free-fall." Snyder discovered that people who are drunk also "appear to have a disproportionate survival rate among free-falls of extreme distances" because they were "abnormally relaxed."Snyder rattles off stories of free fallers the way some tell tales of great sports legends. He recalls that one man lived for ten hours after falling thirty-nine thousand feet when a Boeing 707 exploded. Had the victim received proper medical attention, he would have survived. A Russian pilot fell twenty-eight thousand feet and landed in deep snow on the side of a mountain, where he was rescued by Cossack horsemen. Snyder wrote a whole paper on snow as an "impact attenuator." He says if you happen to fall a great distance, pray that you land in what's known as corn snow, which has large, round crystals from repeated thawing and freezing.Snyder is proud of his career exploring impact forces. His work has helped designers make safety improvements in planes and cars that protect you every day. But he recognizes there's much more work to do. On the one hand, Thomas Magill can fall 39 stories and survive. "On the other hand," he says, "you can trip and fall going out the door and die." He chuckles. "It's kind of an ironical business."