Part of the iconic Colossus roller coaster at Six Flags Magic Mountain in California, US has collapsed after a fire tore through the wooden structure, taking hold of a portion of the ride that was undergoing repair work.

The blaze, which took around 20 minutes to extinguish, caused no injuries, though has severely set back the theme park’s plans to renovate the ride, which closed in mid-August this year to create a hybrid coaster set to open in 2015.

The remainder of the still-standing ride covers around 1,000sq ft (92.9sq m) and when it first opened in 1978 was the tallest and fastest roller coaster in the world. Work will continue on the structure, which once reopened will be rechristened “Twisted Colossus.”

Theme park specialist Rocky Mountain Construction is in charge of the ride’s renovations, which were originally going to see the upper level of the track and right spur changed, with around 3,000ft (914m) of track slated to be removed from the original ride as part of the transformation.

The park was closed on Monday and the cause of the blaze is still being investigated.