Looks like fireblight.
here is some more info I got from:
http://www.ext.nodak.edu/county/cass...s.htm#mountain Fireblight on Flowering Crabs & Mountain-ash What causes a rapid browning of the leaves especially on the tips of branches. The brown leaves will hang on the tree and the stem tips will bend over?
A bacterial disease called fireblight which will also cause the infected twigs, stems and branches tol turn almost black in color.
Which plants are infected by fireblight?
Luckily, the only plants which get fireblight are those related to the apple. This includes pears, flowering crabapples, mountain ash and cotoneaster.
What can be done once the trees are infected?
Once a tree has been infected with fireblight we have only two choices. If the disease is spreading rapidly it may be necessary to prune out the diseased areas. You must cut back 8-12" beyond the furthest advance of the disease. Fireblight is very contagious and is easily spread. If the disease has remained in small twigs and doesn't seem to be progressing, we can just watch the infected areas.
Is there any precautions we should take when pruning?
Yes, we need to dip the pruner or saw in a mixture of 10% bleach and 90% water between each cut to prevent spreading the disease when pruning. After using bleach be sure to wash your pruners or saws with water and oil.
Is there any chemical labeled for spraying trees?
No, the spray for fireblight is only for use on apples and pears.
What can be done to prevent fireblight infection?
Painting pruning wounds will help prevent fireblight from getting in. Over fertilize with nitrogen fertilizer and excessively pruning also increases the chances of fireblight infection.
Will fireblight kill the trees?
Yes, it can kill trees if they are susceptible and we don't prune the disease out as it gets into larger branches.