xXSandmanXx

So I thought it would be fun to watch the giant smokestack structure collapse at the large factory. This structure is easily about 75 blocks high. I removed every bit of supporting structure at the bottom, and even cleared out 3 blocks high of materials. This smokestack is now floating in mid air but refuses to collapse. What am I missing? Is this a bug? Here is a link to the images for review. https://postimg.cc/gallery/Sm7jwq3