A seat assembly includes a first bolster and a second bolster spaced from each other. The seat assembly includes a seat bottom between the first and second bolster. The seat assembly includes a bridge deployable to a deployed position. The bridge in the deployed position is spaced from the seat bottom. The bridge in the deployed position is supported on the first and second bolsters and extends from the first bolster to the second bolster. The seat assembly includes an inflatable device supported by the bridge.