contaminated soil killing shrubs.

I'm not very well up on this sort of thing, but I remember a few years ago there was some virus or something called I think fire blight(?)which was attacking pyracantha etc. I'll google it and see.

Yup, fireblight does attack both shrubs, google it and see if the symptoms match

Bad luck on choosing a plant that dies from the same disease. Try something completely different.

As Bornagain says, both the shrubs are affected by fireblight because they both belong to the Rosacea family. You must not choose another plant from that family to plant in the same area. Please don't ask me for a list of plants in that family! I don't have one, but you might be able to find out by googling or checking out the RHS website when you think you've found another shrub you want. Most garden encyclopaedias give the family under the latin name for the plant anyway, so if you have access to something like the Readers Digest Plant Encyclopaedia, or the RHS one, they should tell you.
Two that spring to mind that you cannot use are roses and cotoneaster - they both belong to Rosacea. Viburnums are okay though, different family, as is Holly, if you wanted berries, and Choisya.

Many thanks for all the helpful replies. I see that I could hardly have made a sillier replacement for the blighted pyracanthus. Murphy's law again! william mcilroy