Demolition of the Dreamworld ride that malfunctioned and killed four people has begun almost 18 months after the incident.

The Thunder River Rapids ride at the Gold Coast theme park was closed in October 2016 when a raft flipped and killed Kate Goodchild, Luke Dorsett, Roozi Araghi and Cindy Low.

Kate's daughter Ebony and Cindy's son Kieran survived after they were flung from the raft.

Development plans, including any kind of monument, for the site are yet to be announced.

The work begins in the same week theme park owner Ardent Leisure forecast a profit in the second half of the financial year.

The company reported a 32.6 per cent increase in visitors and 55.6 per cent rise in revenue between December 10, 2017 and February 13, 2018, compared to the same post-accident period a year earlier.

Dreamworld suffered steep falls in visitor numbers following the fatal accident and the park's subsequent 45-day shutdown.

A year-long Queensland Police investigation recommended no one face criminal charges over the accident, with a coronial inquest still expected to be held l