Colossus, a 36-year-old wooden roller coaster at Six Flags Magic Mountain in Valencia, Calif., caught fire on Monday and partially collapsed.
The park was closed at the time of the fire and no one was injured, Six Flags said via Twitter.
“It’s not something you see every day,” Los Angeles County Fire Inspector Scott Miller told the Los Angeles Times.
“A welder caught Colossus on fire,” an official at the Santa Clarita Valley Sheriff’s Station told Cougar News. “Spectators are blocking roads watching the fire.”
Part of the collapse was caught in a Vine video shared by Jennifer Thang:
Six Flags also said via Twitter that contractors had been disassembling the ride as part of a renovation when the fire broke out.
The fire burned a lift hill, and the collapse left a large hole at the top of the ride.
Colossus first opened in 1978, and the renovation was expected to transform it into the Twisted Colossus, adding steel track to the current wood frame to create a hybrid coaster.
"Twisted Colossus will be the best of both worlds, a modern marvel soon to make roller coaster history," the company says on its website.
It's not yet clear what effect the fire will have on the renovation.
At 125 feet tall, Colossus was the world's highest wooden coaster when it first opened, according to Coaster Grotto. It was featured in a number of films, perhaps most memorably in 1983 as the coaster at Walley World in "National Lampoon's Vacation."
The incident is the second involving a coaster at Magic Mountain in recent months. In July, four people suffered minor injuries after the Ninja coaster derailed. Two of them later sued.