Angry relatives are demanding answers after two construction workers were crushed to death at Brisbane's Eagle Farm Racecourse.
Thursday afternoon's tragedy has also renewed a powerful union's calls for Queensland to introduce an industrial manslaughter charge as it questioned construction practices at the $37 million redevelopment site.
Police and workplace inspectors are investigating the incident in which Ashley Morris, 34, and a 55-year-old colleague were instantly killed when a nine-tonne concrete slab fell on them in a pit at the track's infield.
CFMEU's work, health and safety co-ordinator Andrew Ramsay said it appeared the panels had been inadequately braced before a "shocking sequence of events".
He said the men had hopped on top of one fallen panel when a second came down.
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"There was no escape route for them," Mr Ramsay told AAP. "There was nowhere for them to go. It would have happened so quick."
Family members of the men visited the scene on Friday morning, with Mr Morris's father Keith and sister Maleah demanding answers.
"We're not just going to let this go," Maleah told ABC radio.
"My brother is gone, my niece and nephew are left without a father and my dad has to bury a child."
Keith said his son's partner and two children, aged 2 and 4, were struggling to cope.
"The young one, he doesn't understand at all," he said. "He's asking 'Where's dad? Where's dad?' all the time"
Brisbane Race Club has described the incident as one of the saddest in its 150-year history.
Workers who saw the two colleagues killed have been offered counselling as investigators determine what went wrong.
"There's nothing worse than seeing that," said Mr Ramsay, who believed it was time Queensland had the power to lay industrial manslaughter charges.
Construction company Criscon is yet to comment.
Racing Minister Grace Grace said the deaths were heartbreaking but she had faith in police and Workplace, Health and Safety officers and expected a report quickly.
The BRC on Friday sent its condolences to the family and friends of the men and offered support to the contractors.
Chairman Neville Bell told members jockeys would wear black armbands in a race at neighbouring track Doomben on Saturday.
While the men were not BRC employees, he said they had been part of a team working hard to transform the venue.
Construction work has been suspended but the course was open to trackwork on Friday.
