A popular ride at a Vancouver amusement park malfunctioned mid-air while people were on board Monday.

A mother told CTV News she and her family were at Playland, a theme park in the Hastings-Sunrise neighbourhood, when she noticed something wasn't right.

Irene Morrison said she was watching from the ground as her son and nephew were on the Beast, a spinning pendulum ride. 

"We started to hear a horrible metal cracking-type sound and I knew right away something was wrong because my son has been on the Beast many times and it doesn't sound like that," she said. "It was absolute terror for my sister and I to watch."

On the ride, her son and nephew were also startled by that unsettling noise.

"I was worried that something was going to happen and the entire thing was going to fall apart," said 11-year-old Kirin Dyck.

The ride operator was able to slow the ride down and made it come to a stop, allowing the riders to safely disembark.

Laura Ballance, a spokesperson for Playland, explained the malfunction was a result of a mechanical issue.

"In all cases, when unexpected circumstances happen involving a part malfunction, the part is replaced, the ride is inspected and we go through a process before it is reopened to the public," she said.

When the ride malfunctioned, it also rained down some oil, soaking some riders and those standing nearby.

"I noticed something falling on my arms and I see spots everywhere, then I look up and I get spots all over my face and I taste it and I smell and I say, 'It's oil,'" Morrison recalled.

Ballance said the ride did spill some oil and she apologized to those who were impacted.

The Beast has closed temporarily in the past.

Two summers ago ride called the Fireball broke down at a fair in Ohio, killing a teenager. That ride is different from The Beast, but made by the same European manufacturer.

Playland voluntarily inspected the Beast as a precaution during that time over a two day period.  

"I saw the video of the one in Ohio and the same sound I heard today happened right before the piece of the ride fell in one of the videos I saw. So it hit home how serious this could have been," Morrison said.

It's unclear when the ride will re-open. Ballance said it will go back into operation once officials feel confident it is safe.

Technical Safety BC confirms its safety investigators will be conducting their own investigation.