too catastrophic thing

You can just say "Her losing the spare keys wasn't too catastrophic." If you do want to put a noun on the end then it should be "Her losing the spare keys wasn't too catastrophic a/an thing/event/incident/etc."

Hi GPY..

How is this possible?

MIGHow is this possible?Her losing the spare keys wasn't too catastrophic an event

This is a set pattern: "too + adj. + a/an + noun". E.g. "I didn't have too bad a time", "This is too big a project for me", etc. In the US some people say "too + adj. + of + a/an + noun", which to me sounds wrong.

Similar patterns are "how + adj. + a/an + noun",

GPY"Her losing the spare keys wasn't too catastrophic as an event" is grammatically well-formed, but it has a strange meaning, implying

I agree with you. The 9-11 event was catastrophic.
If I interprete the sentence correctly, it is more natural to say " Losing her spare key wasn't the end of the world".

Thank you GPY and grammarfreak.