On Friday, we learned new details about Thursday night’s terrifying twist to a Six Flags ride.

Prince George’s County Firefighters had to rescue 24 people from the Joker’s Jinx. They were stuck on the roller coaster for hours.

Experts reviewed the tape for us and now they think they know what went wrong.

Demonstrating on a model, experts say the cars got to a low point. Then they just ran out of momentum and stopped.

It’s called saddling or valleying. It can happen for a few reasons. Why it happened on the Joker's Jinx is still unclear.

RELATED: All 24 riders rescued after roller coaster stalls at Six Flags

The-zero-to-sixty in three seconds launch just wasn’t enough for the Joker’s Jinx Thursday night.

Fifteen-year-old Julia Valverde and brother Desi were the first rescued after the fully loaded coaster see-sawed to a stop.

WUSA9's Pete Muntean showed the aerial video to Walt Reiss. He’s an amusement ride inspector and used to work on the Maryland team reviewing this ride. He says this is simple physics.

“It loses momentum. It’s not going lose momentum at the top of a hill," said Reiss. "It’s going to fall down one way or another and it’s going to sit at the bottom.”

The Maryland Department of Labor, Licensing and Regulation last inspected Joker’s Jinx six weeks ago. It says it found three issues that were corrected to get the state’s blessing.

RELATED: Teens rescued from stalled roller coaster say they'll ride again

The state says the coaster valleyed once before in 2014 when debris got caught under one of the wheels. Reiss says low weight in the cars or more friction from wheels can be factors.

"All it takes is one of those bearings to fail," said Reiss. "And you know, that happens sometimes." 

We checked the video again and it appears the coaster got stuck in the same spot as 2014.

The Joker’s Jinx remained closed Friday. Six Flags America is not saying when it will re-start.

After the 2014 incident, a Prince George’s County Judge ordered Six Flags to pay some stuck riders $10,000 in damages.