One of my few friends died with unknown reasons. Would it be unethical to hack their accounts to get more info?

If dark net involved then sure, but they will track your IP as well, but curiosity killed the cat, so go ahead.
If some medical in email, then fine too.

It depends if it was malicious or medical. If it was medical, he kept it secret from you for a reason, but if it was malicious, do what you can. If he seemed off beforehand or long terms away without reason, then chances are he was ill.

Good luck in your search!

If I dare say it and it was malicious I'm sure I would want to know if it was someone in my life. I think you should if you can get in.

God Almighty!! Fucking yes it would be unethical.

Unless you're ordered by law or asked by their family, stay the hell out. I get that in such times we all feel helpless and have so many questions, but there are ways to go about processing grief, and this probably ain't one of them.

@CrankyOldDev you are right. Sometimes in the heat of the moment one's judgement is sometimes skewed