Second generation air bags will have a weight sensor in the seat to tell if the passenger is large enough (heavy enough) that their body can withstand the impact of hitting the Air Bag. IE to sense if the passenger will be injured by the Air Bag, instead of "Saved" by the Air Bag. That is so if your little 8 year old was sitting in the passenger seat the Air Bag will not break their neck (it has happened).Okay, thanks, that what I thought. I was wondering why they didn't go off.
But in this case the car was hit on the passenger side, and there was no passenger in that seat. So I supsect the airbags on that side were not active. That's all I can think of, because the hit was fairly vicious.