Parrot kills Crimson Wing Parakeet

Question
Hi,
I am wondering if you might help me.  I had an 18 year old Crimson Winged
Parakeet.  I got him when he was about a year old.  He was slow and clumsy
but needed a home and was very handsome.  A few months later I took in a
ring neck parakeet and after several weeks of observation I put the two birds
together.  For over two years everything went smoothly until one morning I discovered the ring
neck attempting to kill the crimson wing.  He barely survived but he did and
from that point on I took very extra careful care of him.   Having a special cage
made for him, a daily diet specifically made for him, etc.   He seemed happy even
singing sometimes.   He had continuous medical problems from the attack but
we helped him along and he seemed to be fine but elderly.
    Fast forward to this year.    My adorable 18 (I found him at about 8 mos. old)
year old Yellow Nape Amazon has been going through "puberty" for the past
six years.  He did not want to  be touched and bit all of us severely.  So he no longer
sat on our laps  but I kept him socialized and out
on his open day perch.  I encouraged his curiosity and happy chatter.  The last
couple of months he has jumped from his perch to my desk and asked for me
to scratch his head.  He seemed to be growing up.  
    Although sometimes while we would go for a short walk or a quick dinner he would jump off his perch and
walk around on the sofa or sit on a chair.  He never destroye or did anything naughty.  He never chewed on
books or papers or magazines.   
    Except one time his day perch stand was near my Crimson Wing.   He apparently
jumped on the cage, opened the door and started eating the food and
making mischief.  I heard loud noisy and found him and quietly put him to
bed.  I did tell him calmly I was disappointed and had a long chat.   I made
sure no one ever put his day perch near the Crimson again.
     Last night we all dashed out going in different directions.  Getting in the
car I remembered the Yellow Nape was out with the 50 year old Panamanian--both on
their day perch stands but not near anything.
The TV was on and they had plenty of food and water.  We were only going
to be gone for a few hours.   It's still summer and they had plenty of sunlight.
    When we came home after dark and a few hours later, our Crimson Winged was dead face down on the cold
floor.  He had just passed.  Feathers were everywhere.   Many feathers on his
back were gone and scattered around the floor.  
    The Amazon was on the Goffins cage singing and talking.
     The Panamanian was still on his perch quiet.  Everyone was where they were
suppose to be.   Except the Crimson and the Amazon.
      I am not sure how the Amazon climbed onto the Crimson Wing's cage.  His wings are clipped.
But apparently he did and opened the door.  The food and water were not disturbed.  But the
Crimson Winged either was forced out or escaped.  At that point I have no idea what happen.
I understood and have seen when birds are trying to do injury they go for the feet and eyes.
The Crimson's eyes were fine and the feet were fine.
      I can't figure out what happen.   Why it happen and I am so sad.   I feel so responsible.
I always am so careful with double door entries, cleaning cages and bowls from top to bottom daily.
On and on I treat each bird some with medical needs with care.   I just can't imagine why the Parrot would kill
the Crimson.
      Finally the front of the Crimson was wet.  But a weird wet.  Hard to explain.   We have a white lab that is
about six years old.  He has grown up with the birds and has never bothered with them.   Even when they have
daily cardio on the stairs he never goes near them.  He has never gone after them or a cat (our cats were
locked upstairs on the second floor.  Fortunately, they were tucked in for the evening.  
    Do you have any idea what might have happened or triggered this behavior?
    I can barely look at the Amazon.  He has been caged all day today.  He has a lovely cage with a wonderful
view and lots of toys.  But I know he is wondering why he can't be out on his open perch with the family.
    I am thinking that the Crimson must have been attacked but might have died from a heart attack?
    I don't know and just feel so responsible.  I have spent years taking care of critters.  We have done
so much and then this.   It just has us all crushed.
    Do you have any suggestions?   Where do we go from here?    We have always taken in the abuse and
neglected and for years everyone cohabited in perfect harmony.  
    Thank you ahead of time for your thoughts.
     Sincerely, PM  

Answer
PM,

My only thought here is that the wetness on the front of the Crimson is dog saliva from your Lab.  You have no proof that this was the Amazon's doing.  You didn't mention blood on the Crimson anywhere.  Labs are soft-mouthed retrievers, and I think that perhaps your bird got out of his cage and the lab found him, and when the Lab "retrieved" him, the Crimson died of a heart attack...the fear that he went through was probably so great...and he probably tried flapping which lost him a lot of feathers.

Take care,

Cindy