A man fell several metres while working on the West Keira shopping centre development yesterday afternoon, raising concerns about safety at the site.
Paramedics were called to the Crown Street worksite about 2pm after a 28-year-old man fell nearly four metres.
The worker was treated at the scene for a suspected spinal injury before he was taken to Wollongong Hospital in a stable condition.
CFMEU Wollongong official Mick Lane said the accident came in the wake of ongoing safety concerns on the site.
He told the Mercury workers had complained just last week about issues with height.
"There are obviously problems and the full protection just wasn't there," Mr Lane said. "There are issues ... people are not game to speak for fear of losing their jobs and the end result is what we see today - a big fall."
Mr Lane said he would be on-site today to discuss the incident with members.
"We need to know if it's just one particular area that is a problem or if the whole site needs to be shut down; the problem is that it's got to be built," he said. "We can't live on the job site and the [site's] two full-time safety officers shouldn't have to either; this sort of thing just simply shouldn't happen."
A GPT spokesman said the welfare of the man was the main focus at present.
"We will work closely with the relevant parties to determine the cause of the accident," he said.