Families of people killed at Dreamworld have been reduced to tears at the inquest examining their deaths, after a supervisor from the Gold Coast theme park offered his sympathies.

Key points: Electrical engineering supervisor Scott Ritchie offered families sympathy "for everything you're going through"

Electrical engineering supervisor Scott Ritchie offered families sympathy "for everything you're going through" Both Mr Ritchie and family members were in tears from the statement

Both Mr Ritchie and family members were in tears from the statement Mr Ritchie told the inquest there was a "significant breakdown of procedure" in the ride failure

The inquiry is looking at how the Thunder River Rapids ride malfunctioned in October 2016, killing Cindy Low, Kate Goodchild, Luke Dorsett and Roozi Araghi.

After giving evidence for several hours, Dreamworld electrical engineering supervisor Scott Ritchie asked if he could "address the families" of the victims.

"I sincerely apologise for not being able to make eye contact with you during this time, I wanted to give my evidence without emotion," Mr Ritchie said from the witness box.

"Please accept my sympathies for everything you're going through."

Mr Ritchie, along with some families members of the four victims, were tearful during and after the statement.

Some lawyers representing the families told the ABC they were grateful for Mr Ritchie's words.

When two rafts collided on the Thunder River Rapids ride, four people were killed. ( AAP: Dan Peled )

'You might have done something differently?'

In response to questioning from counsel assisting the coroner Ken Fleming, Mr Ritchie agreed there had been a "very significant breakdown of procedure" relating to the fatal accident.

Mr Ritchie told the inquest that while he was aware of one breakdown of a pump on the ride the day of the tragedy, he was not informed of a second, which had occurred less than an hour before the fatal accident.

Roozi Araghi, Luke Dorsett, Kate Goodchild, and Cindy Low lost their lives on the ride. ( Facebook )

Mr Fleming asked: "That therefore was a very significant breakdown of procedure, wasn't it?"

Mr Ritchie replied: "Yes, sir."

He said he would have taken action if he had been informed of the second malfunction.

Mr Fleming then put to Mr Ritchie: "If in fact on that day you had been given an opportunity to think about it you might have done something differently?"

Mr Ritchie: "I believe I would have, sir."

Yesterday, Mr Ritchie implied the ride's operators were to blame for the fatal incident.

He told the inquest that, in his view, a failed pump was not the cause of "what happened on that horrible day", suggesting ride operators did not follow procedures.

But when questioned by barrister Steven Whybrow, representing Ms Goodchild's partner and the father of siblings Kate Goodchild and Luke Dorsett, Mr Ritchie conceded that when ride operators were under stress they might forget some of the emergency procedures and "make mistakes".

The inquest has previously been told the fatal incident occurred when a pump failed and two rafts collided on the conveyor.

Engineer could have refused to certify ride

Tom Polley, an engineer engaged by Dreamworld to inspect some rides, said he could have refused to certify the ride because of Dreamworld's lack of documentation.

Barrister Matthew Hickey, representing the Low family, asked Mr Polley if he felt he had a "professional obligation" to members of the public who were relying on his certification to keep them safe.

Mr Polley said he "fully" understood that point, but added he did not see any mechanical or structural issues that would have stopped him from issuing the certificate.

The court was shown the Queensland Workplace Health and Safety Regulation stating the annual inspection of a theme park ride must include, among other things, "a check of the log book for the amusement device".

Barrister Toby Nielsen, representing the Araghi family, cross examined Mr Polley: