Condos from a 21st century vantage-point, but I suppose there wasn't much demand for condos/apartments in the 1960s-era financial district, nor much of a history of repurposing office towers.
I too lament the wanton destruction of these beauties, and rank the Singer (and Penn Station) as perhaps the most egregious examples. Also the NY World building and the rest of newspaper row (below):
wikipedia