When it comes to most people's biggest fears, being buried alive is right up there. But the master magician Harry Houdini was no stranger to stunts that would make other people sweat. In 1915, he performed a trick in Santa Ana, California, that saw him buried beneath six feet of earth. It didn't exactly go off without a hitch, however: He clawed his way out—but it nearly killed him.
Stunt expert Steve Wolf considers the buried alive illusion Houdini's most daring trick. "The margin for failure on that is zero," Wolf tells Mental Floss. Wolf is one of the stars of the new Science Channel show Houdini's Last Secrets, alongside Houdini’s grand-nephew George Hardeen and magician Lee Terbosic. In each episode, the trio explores how the notoriously secretive Houdini may have performed his most famous tricks, as well as some of the many mysteries of his life—including whether the magician may have served as a spy, and whether his sad death on Halloween in 1926 was truly an accident.
Wolf, who has served as a special effects coordinator for several films and TV series, is a science educator for kids, and runs his own theme park called Stunt Ranch in Texas, says he's long been interested in how illusions are created and how people perceive reality through visual clues. He explains that when Houdini performed his buried alive stunt (there's some controversy among historians about whether, and how often, the trick was performed), the audience would have seen Houdini enter a coffin, watch the coffin sealed inside a crypt, and then witness the crypt being buried in several thousand pounds of sand or soil.
"A curtain would go up, and the audience would wonder if he was suffocating," Wolf explains. "And after a prolonged period Houdini would emerge, unscathed."
That was the theory, anyway. In 1915, the trick didn't quite go as planned, and there are reports that Houdini fell unconscious after partially emerging and had to be rescued by assistants. But Houdini seems to have been planning a more elaborate, and hopefully safer, version of the trick toward the end of the his life.
For Houdini's Last Secrets, Wolf had to figure out a version of the illusion as similar as possible to the one Houdini worked on later in life. Most importantly, it had to be safe for Terbosic to perform. That was no easy feat, as Wolf explains: "If he's in the coffin and there's truly 3000 pounds of dirt on him and the coffin implodes, that really could cause serious injury. It could crush his lungs, it could crush his heart, he could suffocate."
As with many of Houdini's stunts, there's no surviving documentation, let alone how-to notes from Houdini. That meant Wolf and his team had to rely on problem-solving, engineering, and guesswork to figure out how the magician might have done it. One theory they considered was that Houdini may have used sand, rather than soil.
"Houdini had a traveling roadshow, and sand would have been easy to transport or source locally," Wolf explains. Wolf's team explored a process called sand liquefaction, in which air pumped through sand from the bottom makes sand act like a liquid. That means anything lighter than the sand can actually float.
"Houdini had a background working with compressed air," Wolf says. "And if he'd experimented with this, he would have known you could actually make the coffin float up from the bottom of the crypt and appear on top of the sand silently, just using compressed air to liquefy the sand. We don't know that's how he did it ... but that's one of theories we explore."
The other option, which is carried out in a large-scale stunt on the show, involves trap doors. The first step was assembling the ingredients: In this case, a clear coffin and crypt, so the audience can see what's happening, at least until the curtain goes up. While Houdini would have used glass, for safety's sake the Houdini's Last Secrets team used clear plexiglass, which is less likely to shatter. The transparency also allows the audience to see Terbosic, wearing a straitjacket, inside the coffin, and watch as the thousands pounds of soil are poured on top of him.
"It's not an illusion that he's in the coffin and you see the coffin get buried. That all really happens," Wolf explains.
The secret lies in the way the coffin, and crypt, are built. Each had a trap door—or what Wolf calls "an un-obvious way to get out of the coffin." He explains that since lifting the lid of the coffin against thousands of pounds of dirt would be almost impossible, the best way to get out of the coffin is through the sides or ends. "And if that end were very close to a second trap door, [the magician] could get out of the crypt. Ideally you would want to open the trap door at an end of the coffin, and then apply direct pressure [on a second trap door], and then something would yield, and you'd be able to get out of the crypt," he explains.
The team also employed a staircase, which made it easy to climb up and pour the dirt on Terbosic. But the staircase also helped Terbosic escape—that is, once he'd gotten himself out of the straitjacket. He also had to turn his whole body around, since his head was pointed away from the trap doors. Eventually, he ended up safely inside the staircase, from which he could easily emerge, rub some dirt on himself (to make it look like he'd clawed through soil), and wait for the applause.
According to Wolf, a key part of making the trap doors was using fake welds. "One of the interesting things about the trap doors was creating them as illusions, so people invited up on stage could examine the props and not figure out where the trap doors were," Wolf says. "So one of the techniques Houdini used was fake rivets and fake screws, to make you think something was fastened that wasn't. And we may have experimented with fake welds," he notes coyly. "But anyone who was visually inspecting the props would think they were mechanically sound to keep someone in."
Even once you know how the trick was done, watching it in action in the show is suspenseful. Still, it likely won't quiet the historians and enthusiasts who are trying to understand Houdini's illusions—and his life.
"I believe that most of [Houdini's illusions] are still a mystery," Wolf says. "There are probably only a handful of ways most of them could be done, and through simple diagnostics and experimenting, you could figure out which were safest and most repeatable ways to do each of them. But we don't really know for sure how he did them."
That means the myths—and the legend—of Houdini aren't likely to be buried anytime soon.
The "Buried Alive" episode of Houdini's Last Secrets premieres on January 27.