The gangly-hilarious new Alfred Lerner Hall (replacing the old Ferris Booth)
at Columbia has a triple ramp with inset glass floors, diamond shaped panels
about 18" on a side.  The student I watched ascending the ramp did so with no
trepidation, either because the panes are frosted or because the student was
frosted.

The exterior is made up of 10 foot by 10 foot sheets of glass, "floated" to
the interior frame in the same way Jim Polshek's firm has done the new
Planetarium.  On Lerner Hall, nearest Broadway, there's the largest example
of safety glass failure I have ever seen, truly impressive - perhaps caused
by a frosted student.  What is the theoretical range of such
crumbly-cracking?  A mile?  Could ivy do better?  Why are we still posting on
this topic?  Is the person who original queried on it now full of remorse for
bringing up the topic?  And, Heidi, thank you for sharing.*

Sign me,  Silica Gel

* "I remember seeing this experiment on a PBS Nova show once."