Pic of the bark of mentioned shrub.

looks dead ...

is it in a greenhouse???

i can figure out the structure behind.. but what looks like mother earth below ...

ken

Looks like a pool enclosure. Was it getting heavily splashed with pool water?

Or Round Up? Lorapetulams aren't persnickety. It doesn't matter much as it's dead but you don't want the next fellow to die in the same way.
Cut it down to the ground, dig up the rootball and start with something new. If you are remotely frugal, cut it to the ground and wait 3-5 weeks. If you see anything green, just wait awhile as it will come back from the roots and be bigger than ever.

It is on the outside around the pool cage. The pool over flow pip is approx 2-3 feet away from this hedge. Initially I thought perhaps the chlorine water did this, however during the last 3 year or so of living here it had been fine?

Limeybstd, the white layer in the lower image could be a sign of
Amirilla Fungus.

Died of a root rot.

Not sure if related or not, but shortly afterwards the area closest to this hedge, all the st augustine developed Take all root rot and died.