Southwest plane towed off runway at OAK 7/30

I flew out of Oakland on 7/30, and a number of SWA gates (departing) did a full gate change shuffle. In the middle of all this, there was a SWA being towed, very slowly, off the runway by a tug with an escort of several other vehicles, including a flashing fire truck bringing up the rear. Pretty sure it was an arriving flight, but there was no word about the incident. No flames, no smoke, no visible damage, but I'm assuming there was some reason they couldn't taxi into the gate under their own power. Maybe even just a safety precaution dictated by a misbehaving indicator.

Anyone from that flight, or otherwise, know anything about this?