Arwel Jones, Director of Public Services at the National Library of Wales, told ITV News "our concern now is for the collection", and that it will take time for the extent of any damage to be estimated.
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Charities in Wales say thousands of low-income families with disabled children could be missing out on grants, because of government cuts.
Tuesday will have a murky start with widespread fog, mist and low cloud.
A plan to secure the future of Port Talbot steelworks will be unveiled to staff on Wednesday, ITV News understands.