The most common srs (supplemental restraint system or airbag) failure is the "clock spring" located inside the steering column. This is a taped wheel mechanism that allows wires to stay connected to the steering wheel. The electronics that run through the "clock spring" are for the drivers side airbag, the horn, and any cruise control or radio controls mounted on the steering wheel.
When this "clock spring" breaks, it may interrupt communication between the drivers side airbag and the srs module. We know the cruise control does not work, so try and see if the horn and any radio controls work before bringing the car in for diagnosis. If anything there does not work make sure you tell your shop in hopes to keep the diagnostic part down some.
SRS repairs are usually costly, expensive on cars today is relative though.