I think it is honey fungus, and conifers are listed amongst the trees most
susceptible to it. The fungus attacks a spot in the root and poison spreads
around the structure of the tree (rather like diphtheria or tetanus in
humans)
A tree can die suddenly when under stress or drag on for a number of years.
We have lost forsythia(over one season) and white willow(several yeats drag
on) to honey fungus. The fruiting bodies follow the roots of our Pinus Nigra
in the Autumn, but fortunately the tree next to it, a beech, is said to be
resistant.
There's quite a lot on the internet on honey fungus. It is endemic and the
spores are everywhere.
Bootlaces spread from tree to tree. Underground spread is prevented by
cultivation but one must make sure that the target roots are not damaged.
The fungus is very destructive to monocultures, the classic case being the
destruction of larch plantations around Blair Atholl in the 18th Century.
The larch was imported from the Alps, where it grew at 8000-10000ft, and
was vulnerable under milder/damper Scottish conditions.
David T
"Bobby" wrote in message
...

"WAYNEL" wrote in message
oups.com...
Hi

I have (or had) five pine trees (and another 20 as a fence). Two years
ago one of the pine tree's leaves started to go brown and then 6months
later was completly dead (it was around apx 10-12 years old), I then
chopped it down. Then last year the one next to it did the same thing
and yet again it is dead. I have two others next to it but, touch wood
(forgive the pun), they are OK.

Do you have a good relationship with your neighbours?

Is it possible the trees could have been poisoned?