Cherry Tree Leaves and Fruit Developing Black Spots?

I have a fruit cocktail cherry tree (4 varieties). This year there are many small black spots on the leaves and they are spreading to the cherries. The first leaves and cherries affected are now dead and the spots are continuing to spread. The tree is planted next to a row of arborvitae and a pine tree. The spots first appeared next to the arborvitae. The tree is six years old and I've never had this problem before. What could this be and how do I help.

By Andy from Portland, OR