When you go to an amusement park, you plan to have a fun day and the last thing on your mind is being stranded or injured on a ride. Over 20 people were stranded on the Ninja roller coaster at a Six Flags amusement park in southern California on Monday evening, when it was hit by a falling tree and stopped on the track.

The roller coaster is designed to move like a ninja as it narrowly misses obstacles, water and even the ground. It is supposed to make riders feel as if they are going to crash into something right before it lifts them up or to the side and out of the way.

Roller coaster tracks and other amusement park rides are supposed to be tested and inspected every day to make sure that they are safe and that they will not collide with anything on or near the tracks.

The park has not released a statement about the accident or said what caused the coaster to hit the tree.

At least four of the people who were on the coaster reported minor injuries and two of them were sent to the hospital for treatment. All of the stranded riders were rescued by 8:30 p.m. on Monday evening.

Rescue workers used elevated platforms to reach the stranded riders, attach them to safety harnesses and lower them down to safety.

PHOTO: #Ninja Roller Coaster ride possibly hit tree at CA's Six Flags Magic Mountain. Numerous injuries. Photo: @ABC7 pic.twitter.com/ukNuyH9LDA

— James Dougherty (@Dougherty7NEWS) July 8, 2014

Shortly after the incident, the amusement park updated their website to say that the ride was temporarily closed. It has not yet reopened. Officials are still investigating the accident to determine what went wrong.

Have you ever been involved in an amusement park accident or witnessed one? Do you think amusement park rides are safe?

Image via Wikimedia Commons