The leaves are scorched. This is another indication of lack of adequate moisture.
Is this due to a lack of soil moisture or is something preventing the movement of water from the soil up to the leaves?
A close inspection of the lower trunk shows damage from a lawn mower and/or string weeder. The trunk also was injured by sun scald which killed bark.As can be seen by the grooves in the wood, borers also damaged this tree. These problems have almost eliminated the tree's ability to transport water to the leaves resulting in wilt and leaf scorch.
What can you do to save this tree? Nothing! If it does survive, it will be weak and sick for the rest of its life. This tree needs to be removed. If the decision is made to replace this tree with another, I hope the new tree gets better care than this tree was given.