Before it became a common bucket list to-do, modern bungee jumping was just something that a few daredevils in New Zealand did for fun. Co-creator Chris Sigglekow recently sat down with the filmmakers at Loading Docs to talk about how the activity evolved over nearly four decades.

In 1989, Sigglekow came up with the idea to remove the exterior sheath from a shock cord, exposing the rubber inside. He then used that as an elastic cable for bridge jumping—an idea that he admits he barely tested. In the video above posted by Great Big Story, Sigglekow says that he only conducted one trial, using a potato sack full of rocks, and it did not go very well.

"It just hit the water, split, dropping all the stones...and that was our test," he says. After that, Sigglekow tried out the new bungee cable himself. He hit the water pretty hard, but luckily he did not suffer the same fate as the sack.

As time went on, the bridges that his crew jumped from got higher and higher, as did the stakes. "Newtonian physics had been thrown out the window," Sigglekow told Loading Docs. He also shares a story about a run-in with the police that sparked media attention and led to the growth of bungee in New Zealand and around the world. Check out the short film above to see actual footage from the earliest jumps and to hear more from Chris Sigglekow.

[h/t Great Big Story]