Air Bag Light On problems of the 1999 Hyundai Tiburon

Two weeks prior to accident car was at the dealer to "fix" the reason why his air bag light was on. The dealer "fixed" the light. Two weeks later driver was exiting highway getting onto the on ramp to another highway and for no reason his airbag exploded. The ground was dry and there were no obstacles in the road. At once his hands were forced from the steering wheel and his view was obstructed resulting in him plowing into the freeway barrier. Upon this impact his passenger side airbag deployed. Any help or advice you can give would be appreciated.