Police in Australia have launched an investigation into the cause of a house fire near Brisbane in which 11 people died. Eight of the victims are thought to be teenagers and children; one was just three years old. Two Pacific Islander families from Tonga and Samoa were inside the house when it caught fire. Queensland's police minister said it was "potentially the worst residential fire tragedy in the state's history". Neighbours in the suburban street south of Brisbane said they were awoken by the sound of explosions and screams, then watched as fire devoured the two-storey wooden house, local reports said.