[Zigurd]

If it is a maintenance failure, it's a really big one. You would have to change the tire (really the whole wheel) before this flight, not put the wheel nut on, and not put the wheel nut lock on, and close the wheel nut cover without having done that, probably with a second person there, and have the wheel somehow stay on while taxiing. I think I see the brakes still on the axle in the video, so I suppose this is what happened.

[MBCook]

Oh I agree. The idea of forgetting to secure a tire, even without knowing the aviation specific bits, is clearly a HUGE mistake.

But I just don’t see any other way this could happen unless the tire was secured and just that part of the axle broke off which seems incredible unlikely in general, let alone compared to human fallibility.

[Zigurd]

Axles have failed on landing gear, but the wheels on both sides would be affected. The images I have seen of examples are all due to hard landings.

[seanmcdirmid]

I once saw four tires pop off on a modded hatchback racing down third ring road in Beijing around 2AM in the morning. The only way that could have happened is if the guy just got the car from the shop and someone forgot to add any lug nuts at all. Completely believable in China I guess.