Skyscraper in Japan gets dismantled in near-silence

Why is this dismantling process not in use in NYC? Watch as this Japanese skyscraper gets dismantled level by level in near-silence. The noise created is supposedly no louder than a whisper.

How a 14,000 ton oil rig gets removed from the sea

I am fascinated by giant machinery. Big gears doing big things and big drills digging big holes and big structures dwarfed by even bigger ships. This video has it all. Watch as this 14,000 ton
 (yep, that's not a typo) oil rig gets decommissioned and brought back to shore leaving only those poor little legs behind in the middle of the sea.

PS: What if a ship runs into those leftover legs in the future?