Not just a flat tire after all…

While waiting for the train this morning, I noticed one of the mountain-route line's buses had what looked like a flat. On closer examination, it turned out that it wasn't just flat — it was off the rim!

Two questions came to mind:

1. How are flats (let alone something like this) actually dealt with on a running line?
2. Does the driver have any notification in the cabin when something this drastic happens?

I know buses can be towed — I've even seen it happen once or twice. But with an active (and in this case, express) line, what's the fallback? There will be people waiting, presumably, for that bus, and it's not going anywhere with this tire.

I gather, from talking briefly with a rider from that bus, that there's either no notification, or that it's easily missed. That rider mentioned that the driver said they didn't know when it happened… It's, admittedly, a jump to a conclusion, but it feels like a pretty safe jump to me…