On 9/12/21, I was driving 25-30mph when the SUV in front of me stopped on the freeway interchange suddenly and unexpectedly (other cars were not around us). I hit the breaks very hard and fast but could not stop and collided with the SUV. The front end of the Prius lodged under the back end of the SUV and the impact was enough to wreck the Prius. During that collision, the driver side seatbelt engaged, but the passenger side seatbelt did not. My preteen hit his forehead on the dashboard very hard. Additionally, the airbags failed to deploy. I could smell an odor from the dust from the airbags. The car is at a repair shop waiting for insurance adjuster to inspect. There were no warning lamps or other messages of the problem prior to the failure.