Cornish town bombed date?

[hrossm]

I've searched my references but without any clues so I tried putting 'Morwenna' into MultiMap and it didn't find anything. 'Morwenna Cornwall' into Google similarly failed. So it must be a tiny place (single farm ?) if it exists at all. I certainly hadn't heard of it and I've lived in Cornwall for over 20 years.
One other possibility is that it was not a direct attack but a bomb jettisoned from an aircraft flying to attack (e.g.) Liverpool from a base in Brittany. One such aircraft was shot down in the Boconnoc area.
Sorry, that's the best I can do,
Ross