spruce trees dying?
Blue spruces are, unfortunately, susceptible to several diseases that cause them to decline like this: cytospora and rhizosphaeria. There is information about these diseases at the links provided below.
Fungicides are not effective for treating these problems in mature spruces like this. There is nothing that will help them recover. This area is not quite the ideal habitat for this type of tree, and often the older spruces decline like this, we are sorry to say.