Sitting at the traffic light at the foot of the southbound I-580/US-395 off-ramp to Moana Lane (this is likely the ramp that most of you who drove to the Reno Worldcon via I-80 took to get there), I was looking "upstream" at traffic coming from my left when Lisa screamed "Oh, my God!" and as I looked straight ahead I saw two cars on Moana Lane right in front of us slam into each other head-on.
I had a couple of choices. I could have taken a picture, or I could call 911. Not being a sociopath, I chose the latter, and that's why I don't have a picture of the incident. The light turned green, and I carefully turned west on Moana while making the call. I think that's an exception to the cell phone law, as I did not have a hands-free device. At the first opportunity, I pulled into a parking lot to finish giving details to the dispatcher.
We could see that airbags had deployed, and it appeared as we pulled away that at least one person from the involved vehicles was already was out of their car, as were several others from non-involved vehicles coming to try to help. As a result of my (and probably other) 911 calls, paramedics and fire crews were on the scene within minutes. It's hard to tell (we did not stay), but I think it's possible that everyone may end up walking away from that one, although I expect that both cars were totaled.
Now the Moana Lane-I-580/US-395 interchange is a single-point urban interchange, and can be a little confusing, particularly as it results in a stretch where traffic runs "wrong way." What Lisa said she saw happen was that someone (presumably confused by the layout) pulled into the left lanes too soon, and ended up in opposing traffic. Messy.
After doing what I considered my civic duty to call in the accident (and give my contact details to the dispatcher if we're needed later), we got out of the way and went on to breakfast. That was a scary-looking accident, but it was probably only about 35 mph, and not as scary as the time some years ago that Lisa was driving us on OR-22 east of Salem and we came within a split second of being clobbered by an out-of-control driving coming the other way at full speed crossing over and missing us by less than a car length. (The other vehicle was past us before it had really registered that it was careening out of control on the icy highway; besides any evasive action by us would have resulted in us crashing, too. As it happens, just going straight was what saved us.) We were reminded of this incident last week on the way home from Westercon, as ODOT has now installed K-Rail on the median of that stretch of OR-22 to prevent such cross-over accidents.