We need to know where you are... state?
What your soil is... clay?
To me... It looks like the plants are very close to the concrete.
The fact that they got that large before dying... suggests that the bush was probably fine to plant... Reminds me of shrubs that eventually give up because there's issues with the root zone.
I personally would suggest something native... consider wax myrtle, and yaupon holly. Plant a little further from the concrete, and dig a wide hole.
