The TPMS (tire pressure monitoring system) warning light went off sometime during this mornings' commute, and has persisted since. During the evening commute, I checked the tire pressures, and these were in range (~35 for the front two, ~30 for the back two).

The tires are relatively new (~6000 miles for each). They are the same brand and type that came with the car originally. Looking at them today, the front left tire looked slightly saggy, but the pressure (which I measured 5 times) read normal.

I'm going to call the autobody shop tomorrow, but has anyone experienced this issue before? Any insight into what it could mean?