Firefighters are monitoring damage caused to the classic wooden coaster Colossus at Six Flags Magic Mountain after fire consumed a portion of it, causing a portion of the structure to collapse.
Although the raging flames tore through the top of a lift hill, Los Angeles County Fire Inspector Scott Miller said there appeared to be no immediate threat of the coaster further collapsing.
But firefighters plan to work with Six Flags officials to determine the next steps.
No injuries were reported as a result of the fire, which Miller said was reported at 1:32 p.m.
Aerial television news footage shows fire crews extinguishing the blaze around 1:50 p.m. as a portion of the structure collapsed, opening a hole in the track.
Firefighters often train at the park, but mostly for rescues, Miller said.
"It's not something you see every day," he said of the fire.
Sheriff's officials said the fire was sparked by welders working on the ride, which is under reconstruction.
No park visitors were riding Colossus at the time the blaze broke out -- the 36-year-old roller coaster closed in mid-August.
Less than two weeks ago, the Valencia, Calif., theme park announced plans to revamp it into a hybrid wood-and-steel coaster named Twisted Colossus, scheduled to open next year. Idaho-based Rocky Mountain Construction, which has converted a number of wooden coasters into hybrid rides with looping inversions, landed the makeover job.
Construction crews were slated to remove the upper level of track from the horseshoe turnaround segment of the ride. Similarly, the right spur of track departing from the station is also to be demolished.
In all, more than 3,000 feet of track will be removed from the structure as it transforms into Twisted Colossus.