I used to work as a contractor at that building and the gensets and
battery room are impressive as hell.  Redundant data and power
connectivity from two ordinal directions as well.

I never recall any diesel smell when the gens were running their usual
load tests.  I do however remember when the hvac unit caught fire on
the roof in the winter of 03.  I was glad to be coming in later that
day before having to evacuate.  That was one hell of a ball of smoke:

  High-rise evacuation planning pays off 900 safely leave
  Schaumburg building as fire burns on roof
  Date: February 15, 2003
  Publication: Daily Herald

  Something in their co-workers' voices Friday told employees at
  Schaumburg's IBM building they weren't having just another fire drill.

  As a black cloud of smoke billowed across the sky at 9 a.m., a blaze
  atop the high-rise at 231 N. Martingale Road forced a mass evacuation
  that sent up to 900 workers out into the cold.

  An electrical short in a rooftop heating unit sparked the fire,
  officials said. No one was injured, thanks largely to a Schaumburg...

--
Todd H.  
http://toddh.net/