At work we were talking about when i lost my son at 37. The girl i met when i started working there was saying how it's the worst to lose a kid and i would agree, HOWEVER.... MY son had experienced life. He'd been married, had a kid, was in the Army, held various jobs and played many sports. He died at a relatively "good time" imho - in that he had gotten off track but was steadily making strides towards the Lord again.
Losing a child at 18 is a very different thing.
They have only begun to live their life. Rather sobering for his friends, I'm sure, and will always been a hard thing for his parents and siblings.