You character receives a phone call. The first thing the person on the other end of the line says is the classic sentence: “Are you sitting down?”
Clearly your character is receiving some pretty big news, probably pretty big bad news.
Write down everything your character says during this phone call without revealing the actual message. Don’t write what the person on the other side is saying. For pauses or silent moments you can use some dots or a blank line which will make it read like poetry.