Updated 12am Monday: A man who died defending a friend’s property became the 18th person killed in the NSW bushfires as authorities warned hundreds more homes may have been lost.

The 47-year-old man died of a cardiac arrest on Saturday night near Batlow, southwest of Canberra.

NSW has had the worst death toll this fire season and suffered the greatest property loss, with more than 1400 homes destroyed.

But as bushfires continued to burn across many parts of the state, authorities warned the property destruction could escalate by hundreds.

On Sunday, homes were confirmed lost and a recycling facility damaged south of Sydney after a massive bushfire jumped a major river and quickly overran Southern Highlands communities.

The Morton fire, effectively a new front of a massive 400,000-hectare fireground stretching from Batemans Bay to the Southern Highlands, jumped the Shoalhaven River on Saturday evening.

Local mayor Duncan Gair said there were unconfirmed reports houses and structures were lost in Wingello and more at Bundanoon and Penrose.

NSW Premier Gladys Berejiklian conceded the state was in “uncharted territory” as thousands of people wait anxiously to find out if their homes survived.

“We can’t pretend this is something we have experienced before – it’s not,” Ms Berejiklian said on Sunday.

“The weather activity we’re seeing, the extent and spread of the fires, the speed at which they’re going, the way in which they’re attacking communities who’ve never ever seen fire before, is unprecedented.”

There were 139 bushfires burning in NSW on overnight Sunday with 69 uncontained.

There were none at an “emergency” warning level at 12am Monday but two remained at “watch and act”.

At 10:30pm there are 139 fires burning across the state, 69 are uncontained. 2 fires remain at Watch and Act.

Firefighters, where possible will undertake backburning to strengthen containment lines overnight, pending forecast weather conditions. #nswrfs #nswfires pic.twitter.com/aTmQvZm38x

— NSW RFS (@NSWRFS) January 5, 2020

Earlier

Residents of the border town of Eden were warned on Sunday of a bushfire about to bear down on their area and but an evacuation order was later downgraded to a ‘Watch and Act’ alert on Sunday afternoon.

Despite an easing in conditions in the state, NSW Rural Fire Service commissioner Shane Fitzsimmons warned residents not to become complacent.

“We are seeing an easing of conditions right across the state and there’s even a bit of drizzle down on the South Coast,” the commissioner said.

“It’s certainly a welcome reprieve … but, unfortunately, it’s not putting out the fires and it’s not helping us with furthering back burning and consolidation work.”

Mr Fitzsimmons said crews this week would try and put in additional containment lines before warmer and windier conditions returned by next weekend.

The RFS commissioner said people needed to remain vigilant because “complacency kills”.

A heartfelt story out of the NSW Far South Coast. Chris & Leisa Tague lost their house on New Years Day, and have been volunteering at the local Fire Control Centre ever since. Today was their wedding anniversary. This truly is the meaning of community spirit #nswrfs pic.twitter.com/4n8EEopmbC

— NSW RFS (@NSWRFS) January 5, 2020

Crews are conducting surveys to determine how many homes were lost this weekend, but the RFS suspects it was hundreds.

Areas thought to be hardest hit include Bundanoon, Wingello, Batlow, Adelong, the Jervis Bay area, southwest of Nowra, Boydtown, Kiah, Wonboyn, Towamba and Cabramurra.

A number of hospitals and health services had to be relocated from Tumbarumba, Batlow, Pambula, Delegate and Tumut.

“It was an awful day yesterday – it was a very difficult day,” Mr Fitzsimmons said.

“We are getting reports that the property losses, the damage and destruction, is likely to be numbering in the hundreds as a result of yesterday’s fire activity and fire spread.”

At one stage on Saturday afternoon there were 13 bushfires burning at an emergency level.

“That’s second only to what we saw a couple of months ago where 17 concurrent fires were burning (at emergency),” Mr Fitzsimmons said.

Prime Minister Scott Morrison has been criticised for not alerting fire authorities before announcing the defence force would be deployed to help bushfire recovery efforts.

Mr Fitzsimmons on Sunday admitted he was disappointed about the lack of notice and expressed concern to the prime minister’s office and received an apology.