Based on your photos this looks like fireblight on the apple tree. This is a bacterial disease of apples and pears that destroys blossoms, shoots, and limbs, and sometimes kills whole trees. In general, apple trees are susceptible to a variety of disease and insect problems and requires a spray schedule to manage them. The best recommendation is to select disease resistant varieties.
See our website for photos and more information. http://extension.umd.edu/growit/diseases-apples-and-pears
To manage fire blight we have recommendations for pruning (called ugly stub pruning during dry weather) and spray schedules on our website from Va Tech. It is too late to spray this year.