New Video Shows Boy Plunging 50 Feet at Disneyland's Tiana’s Bayou Adventure

3:35 PM PT -- A Disney official told TMZ in response to the video ... the safety of park guests is their highest priority ... and attractions are designed with multiple safety measures, and teams are trained to respond quickly in situations like this, which they did — the ride was immediately stopped.

We're told as is customary in situations like these, officials with the California Division of Occupational Safety and Health, better known as Cal/OSHA, inspected the attraction yesterday and approved it to open. 

Terrifying new video shows the moment a 13-year-old boy at Disneyland tumbled down a 50-foot waterfall after getting off a moving ride.

The footage, captured Sunday by another theme park guest, shows the 13-year-old climbing out of the Tiana's Bayou Adventure log ride right before the famous drop ... then falling down the water-covered track.

Fair warning -- if you've ever been on Tiana's Bayou Adventure, or any similar log ride, you might want to look away.

As TMZ first reported, the teen was taken to a hospital for evaluation after the incident. Remarkably, he wasn't reported to have suffered any serious injuries and was later released, which is even crazier now that we've obtained the video.