Nesting box

I have a pair of starlings who use my letterbox each spring as a nesting box. Last year they laid a clutch but then for some reason threw the eggs out of the letter slot onto the ground. They built a new nest once I removed their old one but they never laid in it.

This year they came back, she laid 5 eggs and, to much excitement on my part, they hatched - I heard weak peeps so sneaked a look on what I suspect was the very day they hatched. 5 living chicks were in the nest, but a few days later I realised that I hadn't seen Mum or Dad coming out of the letter slot so I checked and all 5 babies were dead.

I was disappointed, but left them there for a few days, not wanting to interfere with nature, then once again disposed of the bodies and the nest. Ma and Pa starling immediately began bulding again and have since laid another 4 eggs. I hope these ones hatch and survive.