Between August 29 and September 1, 2016, Typhoon Lionrock poured a foot of rain onto parts of North Korea causing widespread flooding, the most severe being in the Tumen River which marks, with the Yalu River, the boundary between China and North Korea. According to aid workers from the Red Cross as many as 100,000 people are homeless and 140,000 are in need of disaster relief while 133 people have died and 395 are missing overall. Temperatures in North Korea drop well below zero Fahrenheit in a much of the northern regions in a few months and so the exposure to extreme cold is a high risk. The flooding also destroyed 40,000 acres of agricultural land which will affect food security in the area since the crop is usually harvested in late September and October. The North Korea political prison camps which hold more than 100,000 people may be flooded which puts the prisoners at severe risk, since they cannot leave their camps for higher ground. And because the prisoners are in the lowest class in the North Korean caste system, they will get no disaster relief unless the international agencies insist on it.