Building Demolition

This is the building I first walked into in May 1997 and worked in until it had to be vacated in recent months. The bulldozer has just reached the top floor where many colleagues and I collaborated, argued, won, lost,and generally jostled along together somehow. What's left when this building is finally gone?  The spirits of those who walked its floors, or is this a story I tell myself?  Do buildings remember too?