From sci.chem Thu Nov 28 16:30:06 1996

Lab accidents are generally grim affairs that no one remembers 
fondly.  However I am reminded of one I saw at the University of Kentucky 
when I was an undergraduate there.  A student was walking alongside one 
of the lab benches when he hit a ring stand with his elbow.  The ring 
stand toppled against the riser between two small lab sinks.  The riser 
between the lab sinks was a good place to store chemicals.  A 500 ml 
bottle of concentrated HCl toppled off and smashed into the small sink.  
A 500 ml bottle of concentrated NH4OH followed behind.  A column of white 
NH4Cl rose from the sink until it hit a 12 foot high ceiling.  The entire 
lab was whited out.  The teaching assistants had to vacate everyone until 
the dust settled and could be vacuumed up.  

Carl