So sorry to hear about your co-worker. I hope he makes a full recovery.

I take solace in know that, as scary as the idea of getting hit seriously is, statistically, it's extremely rare especially if you do everything you can to ride safely. I've personally known at least half a dozen people who have died in car accidents over the years (and I'm pretty young), and I'd imagine I'm fairly typical. But no one really lets this realization stop them from driving.