If you were driving on 121 yesterday near Independence you may have seen a few police cars and an ambulance. Per the Dallas Morning News the following occurred:

In one accident, a car driven by a 22-year-old McKinney woman plunged into a creek in northeast Plano (location map), flipping onto its side and dumping the driver into the fast-moving water. Police found the woman about a quarter mile downstream, with several injuries – none life-threatening – and no recollection of what had happened.