There will be approximately 10,000 deaths, 60,000 people would be seriously injured and 200,000 lightly injured, while 9.6 million would be temporarily displaced

A U.N. contingency plan for an earthquake in Indonesia foresees a scenario where 10,000 people would die within 24 hours with 47 million more affected, according to emergency response planning documents.

The U.N.-led exercise to prepare for disaster in one of the world’s most quake-prone regions, is based on a magnitude 7.8 quake in the Sunda Strait, close to the capital Jakarta, similar in size to one that struck the Caribbean this week.

“Within the first 24 hours, approximately 10,000 deaths with a substantial number of missing people is reported,” said the contingency plan based on a worst-case scenario.

A further 60,000 people would be seriously injured and 200,000 lightly injured, while 9.6 million would be temporarily displaced. Although 2.5 million people would need immediate help, fewer than one in 10 would get it.

Electricity and telephone networks would go down for as long as two weeks, and large scale oil and chemical spills would cause fires and disrupt fuel supplies for a week after the quake. There would be major disruption to air and sea ports.