Yes, your junipers could be dying from a disease that attacks junipers but most likely lack of water or root damage from a burrowing mammal damaged the roots. This same problem will affect the next shrub you plant. Try to discover what damaged the junipers by digging them up and checking for burrows, root damage or dry soil. You may need to bring a sample of the foliage to a Master Gardener clinic to check for mites or foliage fungus that could have killed the junipers. My hope is that dry soil or improper planting killed the junipers. Any new tree or shrub will need extra water for year or two as new roots establish. If you decide to replant with any shrub be sure you irrigate at least one inch of water a week. Keep growing, Marianne Binetti