Race to find person trapped after townhouse collapse in Whalan in Sydney’s west

Authorities remain hopeful a person feared trapped in the ruins of a collapsed townhouse is still alive as rescuers continue a desperate search.

The blast on Waikanda Crescent at Whalan in Sydney’s west levelled most of the two-storey home just before 1pm on Saturday, blowing out windows and damaging a neighbouring townhouse.

NSW Fire and Rescue Commissioner Jeremy Fewtrell said crews were hopeful to safely retrieve the person trapped.

“This is still well within the window for someone to survive,” he told reporters on Sunday morning.

“The focus of effort is to really be exploring the building as thoroughly as we can try and make access to either physically inspect or, with the use of our tools, to inspect each possible area.”

Mr Fewtrell also said the rescue teams were hampered by a series of setbacks as the search continued through the night.

“There’s been a range of complications throughout the operation,” he said.

“The job of rescue (teams) is to work their way through and try and find spaces in that collapse area where someone might have been caught.

“And so part of that work involves this sort of very manual labour of piece by piece, picking up the debris and moving that away.”

Complications included a gas leak, safety concerns about how much work could happen at the site and fire underneath the rubble in the collapsed area.

Firefighters have been unable to directly reach the fire because of the debris, according to Mr Fewtrell.

“But we are able to apply water onto that, the water obviously then drains down and suppresses the fire,” he said.

Crews rescued a woman in her 60s and a wheelchair-bound woman in her 70s from the ruins on Saturday afternoon, and later saved a small dog that was in good health.

The women were among five people at the scene taken to hospital - three to Mount Druitt Hospital and two to Hawkesbury District Health Service.

All had been released by Sunday morning as emergency crews continued to search the building for the other person feared trapped in the rubble.

The missing person was on the second floor of the building when it collapsed, he said.

Emergency services were yet to establish what caused the blast.

Firefighters have used seismic monitoring equipment to capture any sounds under the ruins.

NSW Police, who said the incident was under investigation, were initially called to reports of a gas explosion.

Gas mains were isolated at the property earlier on Saturday so crews could safely step up their search and use concrete cutters to remove the debris.