When I had a longer commute: several times.
Broken chain, no tool with me, still near home on the way into work, turned around and walked home
Badly damaged tire miles from home. Possibly could have booted it, but didn't bother, called for a ride
My shorter commute now, I can walk if I need to, or pick up a bus (they have bike racks).
I've had:
Broken chain, but I was carrying an entire new chain (by chance, I had bought it the day before and it was in my pannier- I also carry a chain tool now)
Loose crank-arm - tighten with stupid little multi-tool multiple times until I got home and got out the bigger tools.
I haven't yet broken a frame. Most of my bikes are steel, so hopefully I'll spot a crack long before something fails.