I'll never understand that line of thought. Of course the hotel is not at fault, but it is still responsible to deliver the product they have sold: a room with bathroom, and any reasonable person would expect that running water is available in this part of the world. Therefore, if the hotel cannot deliver what has been sold (and received money for), it should be responsible for compensation. Of course it may be discussed what is reasonable under the circumstances.

Let's just take this one step further: what if you arrive at the hotel only to find out that the entire hotel had burnt down. Would you expect a refund of the pre-paid room or would you just pitch your tent in the smoking ruins and decide that it's not the hotel's fault that there was a forest fire and pay the charge for the room?

"Outside the control of the hotel" does not equate to "hotel is eligible to collect the full amount of the room charge". The guest certainly doesn't have to participate in the entrepreneur's risk of running his business.

HTB.