Venue closed after collapsing on NSW lake

Weddings booked at a popular NSW restaurant may have to be postponed after Milano's On The Lake partially collapsed into water.

Two people escaped unharmed from the large venue just before it slumped into Lake Macquarie, south of Newcastle, on Monday morning, after the pier on which it was sitting appeared to buckle.

The NSW fire service has disconnected power and gas to the restaurant, secured two underground fuel tanks and placed booms in the water nearby.

"That will collect any debris that happens to come out," NSW Fire and Rescue Superintendent Ian Krimmer said.

Emergency services left the site on Monday afternoon and engineers are assessing the structure, which was also damaged in 2013 when a fire broke out in an adjacent boat hire business.

Milano's On The Lake has been closed following the collapse, the restaurant's Facebook page says.

"We are all safe but unfortunately Milano's is closed until further notice," the post says.

"We are in the process of contacting all those that have bookings with us."