Really sorry to hear about your friend's dad. How awful for her and after he went missing. They must be in pieces right now.

All you can do is support her as best you can at this very tough time and keep your anxiety inside as best as you can until you are away from them.

I thought the police weren't suspecting foul play in his disappearance so there is nothing to fear in terms of your own safety so that's all about a high anxiety period as paranoia often exhibits at high periods. Do the best you can to get through the day, go hour by hour, and try to do what you can to calm yourself whether it's engrossing or mundane activities or relaxing aides, etc.

I take it this was a suicide? It's a complex business, it can be nothing about their loved ones and all inside them feeling there is no way out. This isn't a reflection of anything but that poor man's (and his families) struggle, anxiety likes to poke us with questions about whether that could be what we do but it's just thoughts that pop in, they don't have to have any weight and can be dismissed as irelevant.

I hope your friend and her family get all the support they need to get through this tough time. AND don't forget that your anxiety could mean you avoid the situation but you have chosen to face it because it's more important to be their for your friend. That says a lot about you, don't forget that!