Building under Manhattan is a little bit more complicated, since slight vibrations / rumblings can cause buildings to come deviate from plumb.

http://thelaunchbox.blogspot.com/2009/06/june-6-7-2009.html http://thelaunchbox.blogspot.com/2009/06/june-29-2009.html http://www.dnainfo.com/new-york/20120821/upper-east-side/hug... http://www.dnainfo.com/new-york/20130911/upper-east-side/sec...