Hello everyone, I'm wondering if anyone could give any hints as to the cause of the following issue. My mother owns a 2002 Taurs SES, and this morning when she attempted to drive it out of her driveway there was a loud "BANG" from the front left side of the car, and she was then unable to move the car without what was described as a "horrible groaning, grinding noise" from the left front axle. When I came by to investigate I noticed that there were five or six broken pieces of some kind of small greasy plastic part or housing strewn on the ground; for some reason the part apparently decided to violently end its relationship with itself. The only clue as to its identity was that it is white, at one time roughly circular in shape, and one of the pieces has "TOP LH" embossed on it in one spot.

Any ideas as to what might have happened would be much appreciated, before I call someone to get the wounded beast towed off to the garage...