The brakes on this Ram Promaster 2500 failed 100 percent with the pedal going to the floor and not returning upwards. This occurred without warning. The drivers' safety and the safety of cross traffic were at extreme risk. With no brakes, the vehicle crossed through a T intersection and came to an abrupt stop after crossing a ditch and then becoming lodged into a concrete drainage structure. The driver was severely injured and hospitalized. There were no warning lamps or unusual noise coming from the vehicle. The current status of the vehicle is unknown as it was a rental and upon requesting an inspection the vehicle was removed and no access was granted. It is also believed the poor quality driver's seat contributed to the spinal injury of the driver as the seat has no padding and no shock-absorbing capacity and very limited adjustments. Additionally, no airbags were deployed even though the driver's new I-phone 14 pro's SOS feature was enabled, and dialed 911 via satellite due to the abrupt nature of the stop. The contact stated that the correct failure mileage was approximately 38,700 miles.