Two construction workers rode on the back of a falling concrete slab, only to be crushed to death by a second slab at a Brisbane racecourse, a court has heard.
Details of how one of the men allegedly flagged safety concerns also emerged as the pair's boss, Claudio D'Alessandro, faced the Brisbane Magistrates Court on Wednesday charged with their manslaughter.
Ashley Morris, 34, and Humberto Leite, 55, were killed after becoming sandwiched between two slabs in a domino effect at Eagle Farm Racecourse on October 6, according to police.
The court heard Mr Morris had texted D'Alessandro before the incident, flagging concerns that the panels didn't properly fit on their bases in the pit.
It's also alleged bracing on the blocks was grossly inadequate and "never capable of supporting the walls", and the men's only means of escape was a steel ladder set against one of the slabs.
The court was told three panels were already in place and D'Alessandro was on site overseeing the fourth being lowered into position.
"One panel began to fall forward and the two workers managed to scale the ladder on that wall and ride it down and jumped on to its back as it fell," Senior Constable Christian Troeger stated in a document submitted to the court.
"The failure of this wall caused another wall to immediately fall forward as it was no longer supported.
"The two workers were unable to escape the second wall falling and were crushed to death between the two panels."
D'Alessandro was arrested at Brisbane Airport this week trying to board a flight out of Australia, allegedly to go on a four-day holiday to the Philippines.
The company director, who has more than 40 years' experience in the building industry, is accused of negligent work practices which led to the industrial accident.
Defence lawyer Michael Purcell said D'Alessandro had co-operated with the investigation; the allegation was of negligence, not criminal activity; and he wasn't barred from leaving the country when he tried to fly to the Philippines.
Magistrate Anthony Gett did not consider him a flight risk and granted him bail.
"It is clear that the allegation concerns the defendant's criminal responsibility as director and supervisor to the two deceased workers," he said.
"The matter is still in the investigation stage and significant investigations are to continue."
Construction Forestry Mining and Energy Union spokesman Andrew Ramsay, who visited the site on the day of the incident, praised police for charging someone so quickly.
"It's amazing because we don't see many people charged with manslaughter in the construction industry," he said.
The case returns to court on December 12.