Planted a 5yo tree 13 years ago. Early on it had a bit of black on the bark that an agent told me it was the healthiest tree he had seen... in a summer storm at least 3 years ago an apple loaded branch broke off and we sadly trimmed it flush. This year has seen a major downturn. The south side and center didn't leaf out as fully as the rest of the tree. Then we had another branch, not loaded with apples yet drop off the south side. When trimming that up it was noticed that the base of that branch was almost dry rotted. Now a week ago an apple loaded branch fell off the south east side and the branch between the first fall this year and this one is nearly all brown leaves. We have left the recent fall where it's at since the leaves still seem alive hoping to get some apples this year. What I'm most concerned about is if this is a contagious disease or if it's safe to plant a new tree or two.