Bikes are just not as visible as cars no matter how many lights and reflectors you have on. You are just smaller. This is why the law requires motorcyclists to have their headlight on all the time. If you want to be safe on a bike, this might be something to consider. Because your are small, you can easily be hidden behind a windshield pillar. This is one of the reasons that motorcycle patrolmen ride side-by-side, so people will see them. I don't know exactly what happened in this case, but after looking at the location where the accident happened I can understand how the driver could have missed the bicyclist, especially if the bicyclist was coming down the hill at 30 to 40 mph.
A contributing factor in my opinion is the skewed intersection. Renton Avenue has a center turn lane and it would seem easy to make a left onto South 130th Street at such a shallow angle. Instead of stopping, looking, and executing the left turn, a driver would just tend to veer left without stopping (and without looking as carefully). Current road standards call for new intersections to be built at approximately ninety degrees for this reason.
Check it out on google maps. They have the road cameras now ("Street View") and you can look at the pictures as if you were standing in the middle of the street.