The Cambodian communist party was able to seize control of Cambodia after the civil war. It's leader Pol Pot had brought in communism but with major changes. Instead of a industrialized economy, he was looking to create a a country where everyone was a farmer.
Pol Plot forced everyone to move out of cities onto farms and he destroyed factories. This way he was de-industrializing and de-urbanizing. People that were not seen as productive or the ones that weren't able to work were killed on killing fields. This was a mass genocide by Pol Plot.
In 1979, Vietnam invaded Cambodia and overthrew the Cambodian communist party along with Pol Plot. Later on after a unsuccessful attempt at an uprising by Pol Plot, he was arrested and put under house arrest.