I walked into Borders today to look for a book. About 2 seconds after I walked in the door, this huge light fixture falls from the ceiling about 20 feet in front of me, and crashes into a book display. Nearly a half second previous to that, a clerk was walking nearly underneath the fixture. Thankfully, no one was hurt. It appears that over time the fixture slowly worked its way loose and finally, some minor bit of environmental chaos caused it to convert its potential energy to kinetic in a rather dramatic fashion.