I'm sorry for your friend, this is a sad thing to experience.
Similar cases when people die and leave Bitcoin behind in their wallets happen more often. If they haven't left any kind of last will where is instructed what to do with Bitcoins then family and friends might have serious issues what to do with it and especially if they don't have access to wallet. It's a legal.and moral question what to do.
Anyhow, in this case I think their family should decide and they should be offered some technical help to deal with it and its up to them what they are going to do with Bitcoins.
Thats if there is some sufficient or ample amount of coins have been left on the wallet and as mentioned that op is trying out to reach out his parents to tell
about of those coins.
Its just ethical if they would tell them out about it since its their son after all and now its dead then they do have the rights on getting on what he do owns.
Its just sad to hear out these kind of situations thats why its important that we should at least consider finding ways on how our loved ones would inherit our coins
once we passed away.