The husband of one of the Dreamworld tragedy victims yelled "why didn't you stop the ride" in the aftermath of the incident, an inquest has heard.
David Turner was at the park on October 25, 2016 when a raft carrying his wife Kate Goodchild and five others collided with another on the Thunder River Rapids Ride at the Gold Coast theme park.
Ms Goodchild, her brother Luke Dorsett, his partner Roozi Araghi and another woman, Cindy Low, were all killed.
On Tuesday, an inquest heard evidence from attractions supervisor Sarah Cotter that she witnessed Mr Turner yelling at staff following the tragedy.
Ms Cotter, an experienced operator of the 30-year-old ride, said she believed the ride operator on duty had failed to shut down the conveyor in time to avoid the tragedy.
"There was a raft on an angle - for it to be in that position the conveyor must still have been running through all that time," she said.
"I don't think it was ever stopped, or (it was) just jammed stopped."
She also said that in her opinion an alarm button that would alert park staff to an emergency had not been pushed during the tragedy as it should have been.
Earlier, Ms Cotter said she trusted the word of her colleagues that the ride was still safe to operate shortly before it malfunctioned.
She said she had told engineers a pump malfunction was "ridiculous" after it happened for a second time in about an hour on October 25, 2016, the day the four people died.
Engineers assured her the problem was fixed but the ride would be shut down for the day if the malfunction happened again and she gave the all-clear for it to resume.
About an hour later, the ride's south water pump malfunctioned for a third time, leading to the fatal collision.
"I was happy and had the trust in my colleagues that they knew what they were doing," Ms Cotter told the inquest.
"If they (engineers) say it's safe and ready to go, I'm going to believe them."
The inquest continues.