A tier 5 type supplier (small specialized manufacturer) goes down and you first hear about it in the trade news.
It just could be.
Tier 5 is under no obligation to give you production volumes, stock, or customer list. Neither is tier 4.
And if they have a monopoly on their production process, which is common, they are in a pretty good bargaining position.
And the production stoppage will explode through your supply like it does in the MIT beer game.
And 50,000 pissed-off non-customers.
That's the mutuality problem in supply chain.