Woman identified in deadly unit blast as probe goes on

A woman found dead beneath the rubble of a collapsed unit complex has been identified as her family thanked rescue crews for their "tireless efforts" to recover her.

Mhey Yumol Jasmin, aged in her 30s, was found by emergency workers in the early hours of Monday after an explosion levelled a two-storey property in the Sydney suburb of Whalan on Saturday afternoon.

Ms Jasmin's family thanked police, firefighters and paramedics involved in the search.

"We would like to thank all of the emergency services personnel for their tireless efforts over the past few days," they said in a statement on Monday.

"The family is so appreciative of their support, kindness and assistance."

NSW Fire and Rescue Commissioner Jeremy Fewtrell said Ms Jasmin's body had been found in the kitchen area of the home.

"We had information to indicate at the start of the incident that the young lady was in the apartment and from that point on it was a matter of trying to make sure we fully explored every part of the apartment and try to locate her," he said.

Urban search and rescue experts discovered her body after using equipment to prop up a large, dangerously perched first-floor concrete slab. A crane lifted rescue crew members in a cage so they could sweep debris from above.

Using special drills, technicians made holes in large toppled concrete slabs and inserted cameras to look for voids and air pockets.

The slabs were removed by crane giving searchers access under the rubble where they discovered Ms Jasmin's body.

Floral tributes at the scene of a collapsed townhouse in Whalan
Mhey Yumol Jasmin's body was found under rubble by emergency workers in the early hours of Monday. (Bianca De Marchi/AAP PHOTOS)

Emergency workers will continue to clear the rubble over coming days as they investigate the cause of the blast, including whether a gas leak played a role.

Housing Minister Rose Jackson confirmed her department was investigating reports a number of local residents smelled gas in the area in recent weeks.

"I am deeply concerned to hear of accounts from residents who reportedly raised the issue of the smell of gas within the last 12 months," she said.

Ms Jackson said she has instructed Homes NSW to investigate the matter urgently, with the department checking maintenance logs.

Mr Fewtrell previously noted there had been a leak at the site after the explosion, which hampered rescue efforts.

Emergency workers at the collapsed townhouse
Emergency workers will continue to clear away rubble as they probe the cause of the explosion. (Bianca De Marchi/AAP PHOTOS)

Choking back tears, Detective Superintendent Darren Newman said the victim's mother was devastated by the loss and police had been working with her since the collapse.

"Obviously we had to deliver a death message this morning," he said, describing the incident as difficult and confronting for emergency workers.

"We just do the best we possibly can."

Five other people were hospitalised after the explosion, which was felt across several suburbs in the city's west.

Police Superintendent Trent King said the majority of the people who were rescued were under the care of state housing.

Premier Chris Minns described the state of social housing across the state as a "real concern".