Dealing with Losing a Classmate

I've gone to the same school my entire life. It's a very small school, where grades 2-12 are in the same building and around 40 people a year graduate from. My class of 64 was huge for our town, but we were still a very close class.
When the class of 2009 graduated at the end of May, we all thought we'd go our separate ways over the summer and visit one another every now and then.We figured everyone would go to college or find a job and be happy with their lives. None of us saw it coming..
Saturday, one of us died in a car accident. I had known him since day care and he'd gone to the school his whole life as well. When I found out he was dead, shocked crashed through me. I mean, who wouldn't be surprised?
He had a sister, with whom I'm friends with and have graduated with as well since he was held back a year. They were two of the nicest people in the town, and I'm not just saying that. The sister was sweet and soft hearted and the brother was the same. They would always help a friend out and would never mean anyone harm.
The brother was driving home from a bigger town with his girlfriend, which I didn't really know since she was from a different school, when his Ford Ranger crossed the center line for unknown reasons. A semi hit him head on. He died instantly. After the collision, his truck caught on fire. The link shows the accident scene..
http://weht.images.worldnow.com/images/10750070_BG2.jpg
Firefighters managed to get his body and his girlfriend out of the vehicle.
The trucker came out unharmed. The girlfriend was taken to a hospital in critical condition and was later life-lined to a bigger city. She had a lot of broken bones and internal damage, but they think she'll live.

Meanwhile, his sister is so torn up. She was very close to her brother and she is so badly hurting without him. She misses him horribly as does his family. It kills me seeing her so sad along with my other classmates. I miss him too and am deeply saddened. That's why I'm writing this, hoping it'll help.
I keep randomly crying and I'm slipping back into depression. His wake was today. I cannot explain how hard it was to see a classmate laying in a coffin while a friend is bawling her eyes out and looking so sad. Seeing a family struggling like that.. Seeing other classmates and friends upset. God, it's so hard.
I feel horrible about his girlfriend too, even though I never knew her. She has a long and rough road to travel to recovery.
The funeral's tomorrow.
Please, keep the class of 2009 in your thoughts. Keep the families in your thoughts. I will not include names or the location for obvious reasons. If you have any advice on dealing with this, please let me know.
I know I might seem detached writing it, but I just feel so empty inside.