When firefighters arrived they were told two people were trapped inside the blaze. They were able to rescue one of the pair but the other person was dead.
St John ambulance said one person had suffered serious injuries. Another was being treated for moderate injuries and the third person was in a minor condition.
The three survivors were taken to Middlemore Hospital.
A Counties Manukau DHB spokeswoman said two of the three survivors had been discharged from Middlemore Hospital.