Help! Laurel Woes

[minskey]

Help, I don't know what's wrong or what to do with my laurel. I planted it about five or six years ago and it has been growing beautifully. Late last winter one of the laurel bushes started to look poorly, then it just dried up and died [see pic]. Now the one next to it is looking poorly too, it has yellow/pale green patches on the leaves [pic attached]. I'm worried its going the same way as the first and then the whole lot will go . No sign as far as I can see of mildew or bugs. I have a willow next to the dead laurel and it seems to have the same yellow/green patches on the leave [pic attached]

What could it be and what can I do about it.......................

All help is very much appreciated