DC,
That is horrible news. I am so sorry. I can relate to how shocked you are. A couple years ago, my cousin lost his 18 year old son in a car accident. No drugs/alcohol involved, but he was speeding and hit a tree and died instantly. His mother felt even worse because they had an argument before he left the house. Although it was one of those parent/teenager type argument, this is something that she'll think about forever.
Anyway my sympathies. I'll pray for his family.
TIS