Handicapped baby blackbird

This bird is breaking my heart. I've been watching it for a couple of days in our garden. The dad is feeding it and another one, a lively one that flies about. (The mum must have died) Because this one just hid under shrubs and hardly moved, and its head appeared to be drooping all the time, I thought it was weak and poorly and dying slowly. But today I've seen it move and its head is twisted to one side and it appears hunchbacked and so it can't fly. But look at its bright eye!