We had a similar situation, when a mouse we think it was, nibbled a hole in the water service line to the dishwasher. Nothing was noticed, until the next morning, when the tenant got out of bed, and walked into a flooded living room/kitchen. To add interest, we also managed the unit downstairs, which had even more water through out. The upstairs unit had Landlords Insurance, and to make life easy, the assessor for the LL insurerer, was also the assessor for the building insurerer. Now, the LL insurance did not have any cover for temporary accommodation, it was their view, that is why a tenant should take out their own insurance. I did identify however, that the Building Insurance, did provide temporary accommodation cover. The damage bill was then shared between the LL Insurance, and the building insurance. Since then we have been a bit more conscious of plastic water services, and when a plumber is on the premises, we encourage preventive maintenance and had them changed to steel ones.