As mentioned above, an owner or manager of a property is only liable for slip and fall hazards if they actuallly knew or should have known about the hazard, or if they created it. If a customer drops a jar in a grocery store and the person behind them immediately slips on the spilled contents, the store management had no time to address the hazard before the fall happened.
On the other hand, if someone reported a spill in aisle 13 and store employees waited 10 minutes to start cleaning it up, the store should be liable if someone slips and falls on the unaddressed spill.