Can someone please explain to me, a rank amatuer, how a national...

Can someone please explain to me, a rank amatuer, how a national asset that still produces some, albeit heavily reduced income, still has projected growth once Covid is over and still has a very important part to play in the national recovery, with an almost garunteed moat for the next few years, is worth 0?

I'm sure it will go down today. how could it not.
But how can it be going into administration?

And how can it be so bad, when cruise ship companies are still kicking around and haven't gone under?