The responsabilities and liabilities regarding bailment arrangements are very much dependant on the circumstances.
In simple terms, the bailee is supposed to return the bailed property once the expected time of possession is over. If the goods are not returned by then, the bailee is liable for them. However, the responsability of the bailee to keep the goods safe, is reliant on the circumstances. The law of bailment does not exercise a standard of absolute liability.
Here's when the Ordinary Care Rule comes into play. This principle establishes that the bailee's liability should be measured by the standard of "ordinary care under the circumstances". A court will make a judgement based on the specifics of the case to decide whether the bailee guaranteed the appropriate care for the goods or not, in order to determine their liability.
Hope this helps!