The care you gave the trees was appropriate, so we don't know why two of them failed to prosper.  If the sale included a warranty, speak to the seller about it now.  It's past optimum time for fall planting of evergreens so, if replacement is in order, early spring will be the best time to do it.

Thanks for the quick response Bob. Do you think the trees have a fungus.
thanks again,
Fred

We can't be sure what caused the die back.  A certified arborist might be able to determine the cause after an onsite evaluation.

White pine weevil is a possibility, but the damage seems too extensive for that.  See what you think by reading about the symptoms and viewing the photos at the following website.  Look carefully for exit holes or other evidence of borer activity.

http://blogs.cornell.edu/treeipm/2013/07/08/white-pine-weevil/

An additional comment.  The fact that your trees are dieing from the top down would indicate a problem with the root systems.  It is very hard to transplant large B&B trees and if the burlap wasn't removed or the cage clipped or the planting hole properly prepared, any of these can cause problems with your trees properly rooting in.

Thank you very much. Do you think it would be worthwhile to bring in a sample to diagnose?
fred

I would first of all take advantage of your warranty.  You do not want to miss the deadline for replacement.  As Bob suggested, you will need to have them give you a 'rain check' for replacement in the spring.  As far as a sample of a branch, take a good look at them yourself.  If there is an insect or fungal infection, it should be visible, especially if you take a hand lens.  If you see something that looks like the photos in the link Bob sent you, then go ahead an send in a sample.  If not, I still believe it was a root problem.