Guest is demanding a price reduction for a power-cut - What to do?

[Floss0]

Hi Airbnb Community

I have a dilema. We have two guests staying in our apartment in Rio de Janeiro over Carnival for 5 nights. Due to the surge in the number of people in the city and the hot temperature the power died in my building on two non-consequitive nights and now our guests are demanding a discount. The power-cut was the fault of the electricity company - not our fault. 

Both times we did everything we could to react appropriately and resolve the solution and the power was back on as soon as humanly possible.

Should I refund a nights stay or is it something that is not my responsibility to compensate for. It is the nature of a 3rd world city. 

[Gerry-And-Rashid0]

A small refund would be ok - but lets face it, no matter where they were staying in the city they would have had no power!