ROOF SUPPORTED AIRBAG

A vehicle includes a roof and an airbag supported by the roof. The airbag is inflatable downwardly from the roof to an inflated position surrounding a seatback. The airbag has non-inflatable panels and inflatable chambers in alternating arrangement around the seatback in the inflated position. A widest one of the non-inflatable panels is adjacent the back of the seatback in the inflated position. The widest one of the non-inflatable panels is wider in a horizontal plane that the other non-inflatable panels.