I have 4 crabapple tree's, one is looking very sick with dead limbs all over it . It still has some life because it still has leaves on it and crabapples growing on it. But I would like to stop the destruction before the tree dies. Do you have any suggestions on how I can save the tree?
Glenn

Hi! grl4glenn, and Welcome to UDT :)

Can you match any of the leaves with images from this site?
Sick Tree Savage MN

Then you may have apple scab.
If you see tiny holes in the bark, then a type of borer or worm.

Usually, when a homeowner sees these two problems there is only two ways to go.
Hire a professional tree doctor. He's the only one that can obtain the Oils, Fungicides, and pesticides to cure these problems.
I know you don't want to hear this, but you may have to cut this one down to save the other three... If they are not already infected.

Some insight on Crabapple problems:
Questions On Flowering Crab