Indonesia tsunami: Palu hit by 'worst case scenario'
Indonesia experiences earthquakes every day, but the scale of the quake and tsunami which hit Palu on Friday took local people and scientists by surprise.
More than 800 people have died, but the final figure could be in the thousands, say officials.
As scientists explained to the BBC, a combination of geography, timing and inadequate warnings meant that what happened in Palu was a worst case scenario.
A perilous location Earthquakes are caused by the Earth's tectonic plates sliding against or under each other. This is happening constantly, but sometimes the movement is big enough and close... read more