Frozen Pipes...Who pays for tenants one night stay at hotel?

[Chris Cal]

So I have a duplex and each unit is on separate water meters. Today I get a call from both tenants that there is no water and the pipes must be froze. I consulted 2 plumbers and they both say that because the property is on a slab, there is not much that can be done other than waiting for the weather to warm up and thaw naturally which should happen the next day. I already have a tenant complaining about this and telling me they are going to stay at a hotel and make me prorate the rent, can they do this? Wouldn't their renters insurance cover this? The frozen pipes is completely out of my control in a situation like this. They both also state that they left the water dripping but I have no way to prove if they really did or not. I believe the pipes are frozen outside by the meters because both units have no water. If someone can shed some light as to the specific law in VA regarding it would be a great help! Thanks