Police investigators are re-enacting last week's Dreamworld tragedy which claimed four lives at the Gold Coast theme park.

Cindy Low, Kate Goodchild, her brother Luke Dorsett and his partner Roozbeh Araghi died when their raft on the Thunder River Rapids ride flipped over.

Their bodies were released to their families for burial on Monday following post-mortem examinations.

Investigators on Tuesday closed the air space around the theme park while they re-enacted the fatal incident using weighted dummies.

The coroner was also present.

The re-enactment came one day after about 200 Dreamworld staff opted to return to work.

Dreamworld CEO Craig Davidson previously said the park would not reopen to the public until the funerals for the four victims were held.

Shock will stay with people for a long time: Palaszczuk

Queensland Premier Annastacia Palaszczuk said the shock of last week's Dreamworld tragedy would stay with people for a long time.

On Tuesday, in Parliament she thanked Uniting Care Queensland and Lifeline for setting up a dedicated 24-hour helpline in the aftermath of the deaths.

She said it was an absolutely horrific scene and emergency service workers were undergoing trauma counselling.

"The shock of this tragedy will stay with people for a long time and I want to ensure that everything that can be done will be done to assist those people and those families who witnessed this horrific event," she said.