I can see where some things would meet the definition of negligence, like not repairing a hazardous piece of equipment or not deicing a slippery sidewalk. But sometimes I think people file lawsuits for things that aren't negligence at all. Sometimes unfortunate things just happen, and a business owner shouldn't have to suffer financially because of events out of his control.
I was on a jury in a case involving ordinary negligence, and we ended up finding in favor of the plaintiff. The defendant should have put up "Wet Floor" signs around a spill and didn't. We felt the defendant didn't train the employee who mopped up the spill well enough and his failure to warn customers about the hazard contributed to the plaintiff's fall. We agreed on special damages, but not punitive damages.