death of young finch

Question
Hi again Elizbeth:  Why do you think the parents tossed the other finch out of the nest, unfeathered,eyes still closed, full crop, and somehow moved it about 10 in. to where the food and water bowls are?  Did they think I'd be sure to find it because I'm constantly taking the bowls out of the cage?
Thanks again,
Shirley
-------------------------------------------
The text above is a follow-up to ...

-----Question-----
Hi Elizabeth:  We have a pair of first time zebra finch parents.  They laid 3 eggs; one non-fertile, two hatched, but the parents tossed one baby out before its eyes had opened, and the third one grew to be old enough to come out of the nest, and eat a little seed and millet on its own.  This morning my husband saw the baby and the parents all eating millet, then 10 minutes later went back into the room they are in, and the baby was dead.  I have to tell you that as soon as the baby was feathered, I tossed all the pooped up nest material, and put new material in the nest. I'm wondering if the new material somehow signaled the parents that it was time for the baby to feed on its own, because my husband said his crop was empty when he buried him this morning, as if they had stopped feeding him, and I'm wondering if he had been able to get any water, if they had stopped feeding him.  Anyway, what do you think, expert?  My husband and I both love to watch these babies hatch and grow, and the sudden loss of one, especially one so vital such a short time prior to its death, is very sad.  Thank you.
-----Answer-----
Hi Shirley,
  I'm sorry of your news...always sad to see a young one die.  Yes,you're assumption of removing the nest has a great deal to do with this.  The baby will still sleep and spend most of the day in the nest up till about 4 weeks old,and sometimes even longer.  The parents will show the young how to get to food and water but will still feed the necessary food vital for it's growth.  I recommend leaving the nest as is until the babies have grown up fully,about 8 weeks...and removing the material isn't necessary at all,it's the parents job and they take great pride in it!  Sometimes they will re-use the same nest again for eggs.  They clean up all the poop and keep things in order themselves.  
 You can let them have another clutch,and this time I would leave all the duties up to the parents...and you'll enjoy some babies again.
 Just a reminder...never let a hen raise more than 2 clutches  year..she could die of exhaustion..All the best,and good luck,Elizabeth

Answer
Hi again Shirley,
  Sometimes it takes a few tries for new finch parents to become successful.  It's not easy,but you will get used to ditched hatchlings. For some reason the parents will sometimes find something not right, and out it comes...I know it's sad.  The best thing to do is not interfere with the nest while there are eggs,hatchlings or even feathered babies until you know the coast is clear.(at least 6-8 weeks)
 all the best ,and good luck,Elizabeth