It looks like Fire Blight. I had it once on my very large loquat. I cut it back drastically and the disease never came back.

http://blogs.ifas.ufl.edu/nassauco/2017/07/13/q-wrong-loquat/

Oh man! I am quite aware of fire blight. One of my oear trees had it back home. But fire blight up north looked quite different than this. The stems were black as if they were burned. I caufght it early and I guess this hasn't happened yet. Luckily it's all on one single branch that I probably should have pruned anyway. I'll take it to the conservation agent to verify your diagnosis.

Thanks Deb.

Good luck, Bea! Let us know what he says.