<human>: Last night a buddy of mine passed away unexpectedly. I knew him throughout highschool and he had one of my last 2 beers from safe grad when we graduated.  Just last weekend he posted a bunch of pics of him having fun with his gf and brothers. And just like that he passed away. 

Since this is my first time experiencing the death of a friend who I "grew up" with, Im not sure how to try and find out how my friend passed away last night. 

Also this sudden event has made me ponder as to why its part of human nature to wonder about the cause of death of another person.

Give me a shortened version of the text
<bot>: Good friend passed away at 21 last night, OP is wondering how to find out his COD and why humans are so curious about the death of others.