Demolitions are super loud and leave a ton of evidence.

Demolitions involve months of prep and pre weakening the structure.

To get a linear charge to cut steel, they cut into the columns and insert the charge into the cut. You need to direct all the force of the high explosive into the steel or you're just wasting your time. I was miles away from a demolition once and I heard it. It was in NJ and I was in Brooklyn. Demolition charges would have been heard throughout the area..... there's probably a half million people who would have been in the area.