Based on the photos you sent we cannot say for sure what is going on. We notice some old foliage which will naturally shed. We do not know if the copper colored foliage is possible cold damage, poor soil drainage, root issues, etc. Make sure the soil ddrins well in the root zone. 

At this point, we recommend that you scratch the stems and look for green tissue. If it is brown/gray it is dead. Prune back to healthy tissue and look for new growth. Monitor the growth and send us more photos if you notice additional symptoms. 

Marian