The federal government is watching the investigation into the deaths of four people on a ride at Dreamworld.
Cabinet minister Christopher Pyne noted the theme park sector was highly regulated but suggested more may need to be done.
"It is the last thing you would ever think would happen, a terrible tragedy at an amusement park like that," he told Nine Network on Friday.
"Every parent, every Australian has been really affected by that this week.
"In terms of what can be done ... we need see what the police reports are, what the investigation shows, whether there was human or mechanical error and obviously try and do the things to make sure it can never happen again."
Labor frontbencher Anthony Albanese said he and his family had been on the Thunder River Rapids ride at the Gold Coast park, where Kate Goodchild, Luke Dorsett, Roozbeh Araghi and Cindy Low died on Tuesday.
Two children also on the ride miraculously survived.
"At this stage what we need to do is reach out and hope that the families somehow can struggle their way through this," Mr Albanese said.
The Gold Coast theme park was scheduled to reopen for a 'memorial day' on Friday but was overuled by Queenland police because the site remains a crime scene.
Dreamworld owners Ardent Leisure will wait until Monday before making a decision on when the gates will open again.
Ardent came under fire on Thursday after chief executive Deborah Thomas was awarded a performance rights package worth $843,000, including the award of a $167,500 short-term cash bonus for 2015/16.
She later announced she would donate the $167,500 to the Red Cross.
Finance Minister Mathias Cormann said the timing of the bonus was "clearly very unfortunate".
"I'm sure that on reflection the board would accept that," he told Sky News on Friday.
