Hey Farouk, so sorry to hear about your parents accident.

As for the the airbags not deploying from what I can read from your description of the accident then they performed exactly as they're designed to... rest assured Volvo still makes one of the very safest cars in an impact or collision.

Accelerometers that measure the rate of deceleration are designed into the sub-frame close to where crumples zones are located. Only if the nature (i.e. location) and force of the impact are measured within pre-programmed tolerances will the airbags deploy.

In this event, the airbags not deploying probably averted a much more serious accident.