A 27-year-old man arrested on suspicion of arson following fire at home in south Wales, killed Kim Buckley, 46, her daughter Kayleigh, 17, and Kayleigh's six-month-old baby Kimberley.
Police were called at 3:30am following reports of a "serious" fire at an address in Tillsland, Coed Eva, near Cwmbran.
Firemen and forensic investigators are now present at the scene, and officers from Gwent Police will conduct house-to-house enquiries in the area.
The suspect from the Manchester area has been arrested on suspicion of arson with intent to endanger life, and is currently in custody.
Two neighbours tried to rescue the victims before the fire service arrived by climbing up a ladder to the first floor, but were forced back by the flames.
South Wales Fire and Rescue Service said the house was "well alight" when crews arrived at the scene.
Police are asking if anyone has information about the incident or saw anything suspicious around the address leading up to the time of the fire. Anyone who believes they saw something can call 101 or Crimestoppers on 0800 555111.