The law requires property owners to remove hazards within a reasonable amount of time after they learn about them. For example, grocery store managers cannot clean up spills the instant that they happen, but would be liable if they let the spill sit sometimes for even less than half an hour. What is reasonable is ultimately up to a judge or jury. If the hazard, such as construction work, cannot be cleared, owners must warn heir visitors about it, or rope off the area where the hazard exists. https://goo.gl/G1t9BS