2000 Hyundai Elantra seat belts problems

I was driving north bound on highway 99. On a saturday afternoon in rush hour, in sacramento, ca. When I was hit on the rear passenger side by a black nissan. When the cars touched we spun 3 times in the middle of traffic. We were lucky enough to not hit any other vehicle. The car stopped 8 feet away from the retaining wall, facing north bound. My infant (1 month old ) and 13 yr. Old were in the back. The infants car seat sifted about a foot towards the left of the drivers side.

While driving between 35 and 40 MPH, the vehicle was involved in a front end collision, both air bag deployed, but the drivers seat belt, didn't restrain the consumer. The consumer stated the seat belt on the drivers side did not lock in the crash. The driver of the vehicle is 5ft 6in. The consumer broke both sides of his/her chest bone. Please provide further information. When the driver side air bag deployed, it when in the air and did not protect the consumer from hitting the steering wheel.cw