Look up Centralia, PA. A coal seam fire began in the 1960s. Massive sinkholes opened in the streets, and carbon monoxide was constantly poisoning everyone in the town. I went there once. There aren't many houses left, but the ones remaining all look like they have six or seven 'chimneys', but they aren't actually chimneys, they are basically pipes that go underneath the foundation to make sure the gasses don't build up and shift the building. It is a real interesting 'Hell on Earth' type place.