Shrub is turning yellow w/blackspot, loosing leaves & finally dying.Now its happening to the next one in line.?

You didn't specify what the shrub is but it sounds like a blight. Why don't you cut off a sample and take it to the nearest plant nursery. They can probably identify it for you and if it is a fungual or bacterial disease it can probably be treated. If it's caused by a virus, of course, it will have to run it's course.