Jonathan Goodwin's horrific car stunt gone wrong was every bit as shocking as it sounded -- which you can now see here in video of the accident that's gut-wrenching to watch.
TMZ has obtained footage of the moment the stunt got underway Thursday during an 'AGT: Extreme' rehearsal, and the moment Goodwin got sandwiched between two cars ... resulting in a massive fireball to explode, and Goodwin being rushed to the hospital in critical condition.
Check out the clip -- you see the professional daredevil hanging mid-air in a straight jacket ... with the two vehicles also suspended on each side of him. When they release the cars -- which then start to swing toward Goodwin -- they unhook his harness as well.
Goodwin was supposed to fall underneath the cars before they collided, but the timing was off ... and he was crushed between them as they came together. After that, he fell to the ground and hit his head -- but this video, fortunately, doesn't show any of that gnarly aftermath.
As we reported ... Goodwin was unresponsive at first, and folks on the set of the production thought he'd been killed. He did eventually come to, however, while being airlifted to a nearby hospital, where he underwent surgery. We know he was taken to a trauma unit, but his condition remains unclear at this point.
NBC confirmed the seriousness of the accident ... and offering their thoughts and prayers to Goodwin's family. The guy is a longtime stuntman and escape artist -- having appeared on the regular version of 'AGT' with death-defying stunts prior to his migration to this spinoff.