Is that area of rye in the background that appears to be doing well on a hillside or slope? The photo makes it look that way.
If so, there’s your answer. All grains do not do well in saturated soil and/or under water. The general rule I’ve heard with wheat and oats are 1-2 days of either flooding or root contact with saturated soil and the plants are dead. I think this applies across the board with grain as they are all closely related.
Sorry, it’s a bummer but I think basically you had die-off because of the wet conditions. Still time to reseed or overseed if you’re so inclined.
Grouse