It was Gina's cello, which had been out for repair. Her car is also out for repair, so on my way home from South Pasadena I stopped by Stein on Vine, the ancient and honorable music store in Hollywood, and picked it up.
It was in its soft case, which has knapsack straps, so I hoisted it onto my back and rolled off.
Astoundingly easy! And...drivers are politer than usual when you are carrying a cello on your back as you ride!
Gina's practicing on it now.