Phenoxy herbicide damage
24D, mecaprop, MCPA are standard phenoxy's used in 3way herbicide mixtures.
Dicamba is a systemic and in the benzoic acid class /also common in 3 way blends.
Then there are the newer chemistries with fast leaf cuticle penetration and translocation that are in today's blends clopyralid & fluoroxypr / trade names confront and momentum.
Mecamine D is composed of 24D, mecaprop and dicamba, the same as the old trimec 992 - it's rates are 3 to 4 pints per acre ( standard for efficacy with this product ) the only difference are the amine salt percentages slightly.
If the turf is herbicide damaged there will be epinasty ( twisting and curling of the leaf from the rearrangement of cells in the leaf mesophyll ) even monocots such as turf grass can only tolerate so much herbicide. This is a key indicator that the broadleaf material was the culprit.
If the urea did the damage the turf will stay erect and become uniformly chlorotic ( yellow ) at 1st, then become uniformly brown / lose its elasticity or cell turgor from salt damage and finally wilt.
Use these as indicators for the future, hopefully you never experience this again.
Dave Stuart MA/ plant physiology, soil science.