It's our responsibility as cats to help the humans through the sads. Sometimes when humans have the sads, water comes out from their eyes. You can lick it if you want. It tastes kind of salty.
The best thing you can do for your human is to just be there for them. They may want to talk. If so, listen to them. You don't have to say anything, but you can purr if you would like. Sometimes, they don't want to say anything at all. That is OK too. Just be their best friend. They will appreciate the support you give them.
Rest in Peace