2016 Chrysler Town And Country air bags problems

My grandparents were coming home from il monday night. My grandfather drove straight off a turn and hit the ditch into some trees. It had a frontal/roll over. My grandfather (driver) received face fractures, busted rib cage, and a broken leg. He is currently in icu. Grandmother was in the back laying down from just having back surgery. She had a couple fractured ribs. The airbags on the steering wheel and dash did not go off. The side curtain and seat airbags did go off.

Airbag light would light up on and off and then all of sudden stayed on suddenly. Took the van to the dealership and now saying the passenger side airbag wiring harness is bad and needs replaced. But before the solid light when I moved the drivers side seat the light would go off or come on. How can airbag harness go bad.