A devastating 7.7-magnitude earthquake has hit central Myanmar, with aftershocks causing structural damage as far as Bangkok. As Thailand declares a state of emergency, experts weigh in on why some earthquakes are more destructive than others—and whether early-warning systems can help mitigate future disasters.

Myanmar’s economy is in ruins, its education and health systems are a mess and the poverty rate has doubled since the junta’s takeover. About 20 million people — more than a third of the population — were already projected to need some form of humanitarian assistance this year.

The BBC is in Myanmar's capital Nay Pyi Taw to see the destruction caused by a powerful earthquake that struck on Friday. It hit central Myanmar, near the city of Mandalay, more than 200km (125 miles) from Nay Pyi Taw.