I live in an apartment building and the one across from me makes a looud machine sound sometimes. Last night it was louder than ever before and then it stopped for a bit. 20 minutes later it came on blasting what I would say dangerously loud, and I looked at the top of the apartment building from me and white smoke was billowing out the chimney. There was no smoke smell or 911 called so it wasnt a fire. I am just concerned cause I have no clue what this sound was and it sounded dangerous. It sounds like a broken ice removal truck that is about to explode.