Traveling 25 mph avoided a deer, slid on some leaves and struck a tree. Drivers side airbag deployed striking me in the chest fracturing my sternum. My seat belt free spooled. Passenger side seat belt locked up although only the drivers side airbag deployed. After my release from the Trauma Center I went to get my plates and personal belongings from the H3 and was asked if I was wearing my seat belt, it was stated that whenever an airbag deploys the seat belt is supposed to lock up but in my case it did not