2012 GMC Acadia engine problems

My wife and three daughters, ages 11, 9, and 6, were involved in a major crash. An elderly male traveled thru a steady red traffic signal and struck the passenger side of my wife's vehicle as she was crossing the intersection with a green traffic signal. After impact, they were pushed head on into a traffic standard (which was taken out completely) and then into a telephone pole, also head on. Not one airbag deployed. The vehicle is supposedly equipped with front and side airbags.

Tl* the contact owns a 2012 GMC acadia. The contact stated that three days after the vehicle was purchased, the contact was unable to start the vehicle. The contact also stated that the check engine warning light later illuminated. Additionally, the air bag sensor light illuminated while driving at an unknown speed. The vehicle was taking to the same dealer, where the front passenger's air bag sensor was replaced. The sensor failure recurred several times and the dealer referred the contact to the NHTSA.