“It wasn’t like the buildings were falling down,” said Bankston, who noted that demolition needs to be done carefully to avoid creating risks of collapse, such as by overloading floors with heavy debris.

He said his company left the project about a month ago amid a financial disagreement with the general contractor.

At least 60 firefighters responded to the collapse.

via Building Under Demolition Partially Collapses in NYC; 1 Dead – ABC News.