Collapse risk not detected at NSW marina

A business owner at a NSW marina that partially collapsed into water thought the building would have been condemned before Christmas.

The two-storey building at Pelican Marina slumped into Lake Macquarie on Monday morning, two months after a structural assessment report failed to identify the risk of collapse.

Boat broker Jim Sommers, owner of Marine Sale Solutions, said his office on the bottom deck was completely destroyed.

But he said he didn't see anything that suggested an imminent collapse when he was working there on Monday morning.

"There were no cracks in the wall. The doors were opening fine," he told AAP.

He left his office about 20 minutes before the building collapsed, but an accountant and an elderly female resident who were still inside narrowly escaped.

Mr Sommers said Crown Lands, owner of the site, took over the marina in early December and did an inspection of the building.

"I thought it would be condemned," he said.

"The pylons were held on by ratchet straps."

A spokesman for the Department of Primary Industries said on Tuesday "the structural assessment report in December did not identify risk of collapse to the building".

A number of the safety upgrades recommended in the report had been completed, he said.

The building is being stabilised so it doesn't slip further into the water, although the northern end of the building is still too unstable to be accessed.

"Inspections are continuing to determine if demolition is required or if the less damaged southern end can be repaired," the spokesman said.

A popular restaurant and wedding venue at the marina, Milano's On The Lake, is closed indefinitely following the collapse, leaving brides-to-be looking for alternative options.

Lynne Williams said her stepdaughter had always wanted to get married on the water.

"Now she's got a wedding in the water," she said.

"You have to laugh or you'll cry."