Is there a question here? :-))

Older exterior leaves on established flax plants (Phormium spp) can become lax and begin to lay on the ground - nothing lasts forever, even with evergreen plants - and will sometimes need to be removed or pruned off. Same with older fronds/blades in the interior.

But beyond that, without a photo to illustrate the problem or a much more descriptive explanation of what's going on and current growing conditions, there is not much to comment on.

Agreed that photos would be helpful. One thing that comes instantly to mind is gophers. I had a flax that over a three day period went from being completely upright to having all of the leaves laying flat on the ground. A gopher had eaten most of the roots.

-Brett

Might just be the heat. My flax are looking pretty sad in zone 10a. Where are you?

Another thing to check is for is an infestation of New Zealand flax mealybug. They live in the base of the sheathed leaves. They can weaken a plant enough to eventually kill it.

Has it been drinking?