Redbud grows so quickly that I would trim the dead branches and allow the remaining growth to fill in again. The regrowth will probably require some minor pruning work in fall to help your tree get back to a more conventional shape. Forest Pansy is NOT one of the hardier varieties.

I'm puzzled as to why they died. Does the tree have a disease? Is it planted in the wrong spot? Do you have gophers?

make sure the remaining part of the plant is not rootstock.

Thanks much for all the replies! I had to google some of the terms: I might have gophers, but not sure (if I do, how to get rid of them?) It is on a raised mulched bed. Other shrubs on that bed seem fine except this tree and another shrub that died last yr. It is on the east side of the house and does not get afternoon sun. Gets water from a sprinkler. I searched but cannot figure out what is rootstock and how I can find out...

Some years ago I had a Chinese pistache tree that had been growing beautifully and one spring after leafing out all the leaves drooped. Upon close inspection I could see tiny holes around the trunk below where the branches came out. It was infested with some sort of beetle. I cut the tree below the holes and treated the tree around the ground with a systemic product to target the pests. There was one branch unaffected as it was below the infestation. The tree rapidly grew more branches. Don't give up...look for suspicious damage.

Redbuds are prone to a fungus disease called verticillium wilt. If you cut off a diseased branch and you see a brown discolouration it is 99% sure it is verticillium. There is no cure for verticillium.

Wood Discolouration Caused By Verticillium

I checked one of the dead branches and there is no sign of Verticillium (as in the link you added.)

The brown discoloration of the vascular tissue in the center of the branch is not always present with Verticillium. More often it appears as brown streaking just under the cambium layer but it never hurts to check further. This is not always an easy pathogen to diagnose so I'd suggest you take samples of the dead branches (together with the above photos) to your local extension service office for a professional diagnosis.

I have the same problem. What did you do with the tree?

My pansy didn’t come back either after the hard winter. This would have been its 4th winter. It too is in a berm and gets full sun. It was beautiful last spring but feel the harsh summer caused sunburn. Is that possible?