I knew something was up when my back end was sliding/rolling side to side when I hit any bump and when I put my feet down the bike was definitely several inches lower.
After fenangling a ride home so I could use the car to get to my meeting late Irene and I used a friend's trailer to bring it to the shop. (Thanks MW!)
Luckily, the shop was able to get it's hands on a tire which is really quite hard these days because scooters are gaining in popularity so fast the tire manufacturers can't keep up. And so 150 bucks later I am back on the road.
As a not-so-funny aside, I thought for a bit that the screw was one of my own drywall screws but it is definitely a flooring screw - phew.