A stop sign at the front of Wollongong Hospital's sleek new foyer greeted staff and visitors on Monday after flooding caused the closure of the main entrance.
A source told the Mercury that a leaking roof on Saturday night forced the foyer to shut just two days after it officially opened.
Cleaners arrived on Sunday morning to mop up the mess, but the new polished entrance was still closed to the public on Monday afternoon.
The stop sign and yellow caution tape warned visitors not to enter the foyer and a sign on the front door redirected them to a nearby entrance on another level.
The new foyer, off Loftus Street, was unveiled to the media for the first time on Friday as part of the hospital's $106 million redevelopment.
Wollongong Hospital general manager Nicole Sheppard said the new foyer marked a "major milestone" in the redevelopment, which is due for completion next year.
A spokesperson for the Illawarra Shoalhaven Local Health District said although there was no damage to the foyer it had been closed for safety reasons.
"Extreme weather conditions including rain driven by high winds saw water leak through an adjacent construction site," the spokesperson said.
"There was no water damage to the foyer but because it's a main thoroughfare it was closed as a precaution to minimise risk to the public."
Water caused damage to the adjacent building site.
Management and the contractor are working to rectify the issues.