Bungee jumping involves jumping from a tall structure while attached to an elastic cord. The thrill comes from both the free falling and bouncing back up. When the person jumps, the cord stretches to absorb the force of the fall before snapping back to bounce the jumper up and down until their energy is dissipated. Modern commercial bungee jumping began in the 1970s and has had millions of successful jumps since, though injuries can still occur if safety procedures are not properly followed.