Lack of water is the obvious answer this year. Gently pull the dead material from plant. If you cut the branches they will not re grow. Spider mites can also be a problem in dry weather or very damp weather. Next summer hold a white piece of paper under the branches shake the needles. If you see tine red dots that move, you have spider mites. Spraying the tree with a stiff stream of water will dislodge them. Repeat every three days, till not more spot appear on the paper. Best And Happy Yardening, Nancy.