Four teens set fire to an 88-year-old woman's home as she slept in West Auckland.
The elderly woman had earlier offered a glass of water to the group.
Police say they are investigating the torching at Ranui woman's home late on Sunday night after she had gone out of her way to help three girls and a boy.
Detective Senior Sergeant Roger Small said the woman the 14-18-year-olds knocked on the woman's door about 10pm on Sunday and asked for a drink of water, which she gave them.
Shortly after they came back to the house but she asked them to leave.