C320 Airbag Deployment Question

[767Flyer]

My Mom and younger brother were involved in a head-on accident in her 2001 C320 going about 40 mph - she was driving and didn't have her seatbelt on (why I don't know) but my brother did (passenger seat). Thank God they're both ok. For some reason NONE of the airbags deployed. I don't know anything about the new C class MB (neither does she). Does the fact that she wasn't wearing her seatbelt have anything to do with the airbags not deploying? I thought it would at least deploy on the passenger side, but didn't. Anyone have any answers? The cops and paramedics at the scene were shocked that the airbags didn't pop. An older Toyota Corolla full of teenage girls weren't paying attention and drifted into my mom's lane at hit them head-on. Their airbags did deploy and burned the skin on their faces and arms pretty bad.

Cars can be deadly weapons - obviously I'm mad that my mom wasn't wearing her seatbelt, mad the airbags didn't deploy, etc.

Thanks for any info.

Mark E.
Miami, FL