That's awful Phil - so disappointing. scrape a little bark off a branch - if its dead the branch is dead but if it is still green there is hope. (Though not a lot if there are still no leaves at all)
There must be a reason why all three have struggled - how were they last year?

leafy last summer. may have over watered. am told that they can spend ages looking awful. hence the question. thanks for your help. philip

will do thanks