This story is part of an ongoing Quartz series on how China is reshaping our world. Over one February night, in the northern Chinese province of Hebei, 5,600 pigs were slaughtered and buried in a mass grave. Similar executions have been carried out all across the country to try to stem the spread of African swine fever, or ASF. The virus doesn’t affect humans but kills nearly all pigs it infects. In just a year, ASF has wiped out about half of China’s pig herd, the largest in the world, and has since spread to neighboring countries in Asia. It’s causing huge price hikes within China and massive disruptions in the global market for meat. Although there is no vaccine or cure for ASF, the sheer scale of the crisis can be blamed, at least partially, on the rapid pace of economic development in China and bureaucratic ineptitude. China’s fragmented agriculture sector has gone through a rapid expansion in the past two decades, but over half of the pigs in China are produced in small backyard farms with low biosecurity standards. And as we show in this Because China episode, there was also rampant underreporting of the growing problem at different levels of the government, due to perverse incentives built into China’s bureaucratic system. The ASF epidemic offers a rare window into understanding China’s fragmented, underdeveloped agriculture sector, and how it can have a major impact on the global trade system into which it’s now deeply integrated. For our latest episode of Because China, Quartz takes viewers inside one of the largest Chinese pig farms devastated by the deadly virus to explain how things went so badly wrong.