Dreamworld horror: What really happened

Investigators have said multiple factors contributed to the Dreamworld tragedy last week.

Human error, mechanical malfunction and maintenance and operational issues combined may have caused the death of four people, the Courier Mail reports.

'Often in a catastrophe like this, you get a combination of contributing factors where the planets align horribly,' the source told the publication. 

'(Possible) electrical problems, pump problems and human problems including compliance with policies and procedures are all being investigated.'

The news comes after the coroner attended the re-enactment with crash test dummies at the theme park.

He concluded that a conclusion could take a ‘long time’ but hopes an inquest be held held as early as next year.

Canberra mother Kate Goodchild, 32, her brother Luke Dorsett, 35, his partner Roozbeh Araghi, 38, and Sydney mother Cindy Low, 42, were killed after the Thunder River Rapid ride malfunctioned and flipped backwards.

The first victim’s funeral is being held today.