House Martins' nest unattended after sparrowhawk attack

Hi, I saw a Sparrowhawk take an adult House Martin from right by its nest yesterday, and I haven't seen a Martin go in since. There is a fluffy head sticking out of the nest and I think it is a chick with others in there, as they are making a noise when other Martins are around. The nest is about 5 metres off the ground on the side of a house. Any suggestions, would the local RSPB intervene? Thanks.