Abstract: A seat back for a motor vehicle having a tower extending upwardly from the seat back upper end along one lateral side of the seat back. The tower contains an inflatable air bag which is deployable to provide head side impact protection for a seat occupant. By mounting the air bag within a raised tower, the air bag is deployed from a higher location in the seat back to reduce the possibility of interference between the air bag and a shoulder belt. Furthermore, by not mounting the air bag to the seat back head restraint, it is possible to provide a fully adjustable head restraint attached to the seat back and extending upwardly from the seat back upper end. A removable side bolster is also provided which covers the air bag canisters mounted to the seat back frame. Following deployment of an air bag, the bolster and air bag canister are removed and replaced with new components. This enables the seat assembly to be repaired without replacement of the entire seat assembly or seat back.