It's a disaster that can't be predicted beforehand but that doesn't mean we have to feel anxious about it because even though there is a possibility of unexpected events happening but we just hope that something like that never happens to us.

Talking about the security of seeds or phrases in the end it comes back to each of us personally.
Losing your phrasebook is a problem but eventually we'll realize that it's still the best way to go about securing our phrases.

When talking about backup it is optional because if you need it then do it but when you don't feel this is needed then it doesn't matter as long as they know the risks that will occur and even in some cases we also often see discussions about memorizing seeds or phrases. I personally still do that where I write at least a copy to keep in a safe place, even though some people think it might not be necessary but I still feel that it is important and this is just to make me more comfortable so that when my seed or phrase is lost or damaged then I still have a backup for it.

People who live in areas that are affected by natural disasters should prepare. How about people who don’t expect or experience such incidents, like the one that happened in LA, which no one was expecting that tohappen? It’s just safer irrespective of where you live or base or what method you use to secure your bitcoin to make multiple backups so that if access to one is blocked or lost, the other will come in as plan B and C. Anything that has to do with money, we should always consider every possible option.

When such happens the first thing I think of is creating an alternative, like the victim should be able to provide another environment that contains the private key. Even when considering an alternative people still intend to place this information in a different area and same building meanwhile If anything happens to the building like op example everything is gone, no one will love to experience any kind of bad situation as such even relatives. Well separating this information is valid and how sure is the substance carrying the details save meaning how long will this last for years is also important honestly the paper kind of work is the least due to the soft texture anything can happen.

Those who are in need would learn things up and do things differently.
Those who are not - would be using custodials and or even ETFs.. which, in my opinion, is even a bit worse than buying actual Bitcoins.

Paper is temporary.
Good metal is almost eternal.
 

Although it is indeed a good thing because we will be more careful and more alert to protect assets and their scope such as seeds or phrases because calling it is important but worrying too much about things that are not certain is also not very good so in the end in this case we will actually become paranoid ourselves because of something that is not even certain to happen.

Prudence is important but it does not mean that we should also feel too worried about situations that are only based on things that are not certain or even not happening to us because after all, a disaster like what happened some time ago cannot be predicted.

We do have to be more observant and more protective in protecting the assets we have so that we are more comfortable and do not feel haunted by anxiety that seems to be actually an excessive thing.

Would you get only one or multiple pieces to store them somewhere?

Would laminated paper withstand fire or things like it?
That would be the answer to what to choose, however, it's only as to make the biggest precautions of what can happen to the info you want to store in any situation.

I find this story very strange, because I think that she could have stored part of the phrase in a cell of one bank, and part of the phrase in a cell of another bank. Thus ensuring the complete safety of funds. Well, I understand that maintaining cells in a bank costs a lot of money, but it really makes sense. And if such a grandmother did not have much in the account, then I think it makes no sense to grieve over the lost funds in Cryptocurrency, because it is not comparable with the house

Multiple iron plates with your private keys are more like it, if we go for the options that would involve risks like that.
They are rare, but they are still there.