The folks over at Thirteen/WNET have produced three short web documentaries about the decline of manufacturing in NYC. The manufacturers profiled in the pieces are all currently in Brooklyn, and struggling to keep their businesses going. There's Angel's Bakery in Greenpoint (inventor of the muffin top!) trying to find affordable rent now that the area has been gentrified, metal fabricators Milgo/Bufkin (here's a map of their metal work around the city), and beach umbrella makers Embee Sunshade (watch below).
They also take a look at NYC factories in the past/in their prime and in their current state (surprise, surprise...some have become condos!), and have an interview with a planning expert from Pratt about zoning laws.