Floods.

Hundreds of people have been killed or gone missing in the worst flood to hit North Korea, the country's state media said. 
The Korean Central Broadcasting Station (KCBS) reported that the flooding in North Hamgyong Province left hundreds killed or missing and more than 68,900 stranded, making it the worst disaster since Korea's liberation from Japanese colonial rule in 1945. 
The flooding also destroyed more than 11,600 buildings, severely damaged some 180 sections of road and more than 60 bridges, and disconnected electricity and communication lines. 
The heavy rains were brought by Typhoon Lion Rock, which swept across the region from Aug. 29-Sept. 2, KCBS said.

Source : QNA