A vehicle includes a vehicle pillar. The vehicle includes a vehicle roof supported by the vehicle pillar. The vehicle includes an airbag supported by the vehicle roof. The airbag has a first side portion, a second side portion spaced cross-vehicle from the first side portion, and a front portion extending from the first side portion to the second side portion. The vehicle includes a pyrotechnic device supported by the vehicle pillar. The pyrotechnic device is coupled to one of the first side portion or the second side portion of the airbag.