Had a fire in a Queenstown house happened earlier in the morning, there could have been ''multiple fatalities'', the Fire Service says.
A fire investigator yesterday said the Hallenstein St house, where a 28-year-old woman was seriously burned on Sunday while dragging a burning mattress out of the building, was fitted with 10 fire alarms, but none were working.
Fire risk management officer Stuart Ide said the 10 smoke alarms in the two-flat Hallenstein St property were ''missing from their brackets, had the batteries removed or the batteries [were] disconnected from the connections in the alarm''.
New Zealand Fire Service area commander Keith McIntosh said had the fire happened early in the morning when people were sleeping ''we could have been dealing with multiple fatalities here in Queenstown''.
Queenstown Fire Station Officer Roydon Cullimore told the ODT on Sunday the woman had fallen asleep with her hairdrier on and woke up when her mattress caught fire.
Three fire engines and 12 firefighters attended the scene after the woman's flatmate raised the alarm shortly before 1pm.
Mr Ide said it was ''almost frightening'' to think of the worst-case scenario.
''People would look at a smoke alarm and think 'yep, that's going' ... and yet somebody has gone along - we don't know who - and disconnected the batteries and taken them off the ceiling.
''Why do people do that?
''If the battery's failing there's a warning device, which usually does go off in the early hours of the morning. You take the smoke alarm down, you put it on the table and you get a new battery the next day.''
Mr Ide said the landlord had replaced the batteries - and would have done so earlier had they known there were issues.
He said it was a timely reminder for landlords to ensure smoke alarms were checked - changes to the Residential Tenancies Act, coming into effect from July 1, 2016, would mean it would be illegal not to have working smoke alarms in tenanted properties.
Housing Minister Nick Smith announced the changes in July, making landlords responsible for ensuring ''operational smoke alarms'' were in place, with tenants responsible for replacing batteries and notifying landlords of defects.
Dr Smith said the Ministry of Business, Innovation and Employment would have new powers to prosecute landlords for breaking tenancy laws as part of the reforms, particularly where there was risk to the health and safety of tenants.
Mr Ide said he would wait until the woman, who was out of hospital, had improved before he interviewed her about Sunday's incident.
While she had ''tried to take the initiative'' in removing the burning mattress ''it's not the right thing to do''.
The mattress became lodged in a doorway.
''She, along with another occupant, had to go to a balcony on the first floor of the house to await rescue ... because there was no other way out.''