How did the pigeon on my balcony die?

A mom pigeon bird laid two egg on my balcony. One egg was cracked. The other egg hatched. That bird grew to about a few months old and sits on the roof of the building next door. Two more eggs were found in the nest that hatched. Two more birds came out. One flew away but the other one just sat on top of a box over the nest never flying. It seemed the mom or dad bird was trying to get it to fly for weeks but it never flew. It just stayed in the corner. It looked sad and hurt. Two more babies were born. The mom and dad have been feeding the two new babies. This middle bird's brother or sister flew off never to be seen again. Every time I would leave out food, the bigger birds would come and get it. Yesterday, we found the middle bird dead with it's eyes plucked out : ( My husband says he thinks the dad did it so he wouldn't have to feed it or possibly that they were frustrated that he wouldn't fly away. I was thinking maybe a crow got to him. Would the mom and dad have been so busy feeding their new babies that they forgot about him and he starved? My husband says the bird was brutally wounded : ( What are your thoughts?