Body problems of the 2000 Nissan Quest

I start driving very slow out of parking space when the car accelerate by itself, reaching high speed within seconds, the brakes did not work at all,foot pedal or emergency brake. It seems that the accelerator pedal was stuck. My foot was not in the accelerator but car continue increasing speed. I have no choice to collide against another parked car and hitting a wall where finally the car stop. Even when the car got to stop against the wall, the engine continue running accelerated until I finally shut off the engine.

An f-350 ran a stoplight at 50 mph and impacted the front driver side of van at the tire. The van turned upon impact and received the balance of the impact head on with concentration to the left quadrant. Further spinning, the van then impacted the side of the offending vehicle. Complaint: the air bags did not deploy. She was wearing her seat belt. She sustained injuries to cervical, thoracic, and lumbar regions of back. She was treated for 2. 5 months and then released. Her head hit the driver side roof, thankfully, just above the window resulting only in bruising. Her muscles were sore from head to toe for about a month. It is quite possible that these injuries would have been minimized by airbag deployment. High impact crash to the bumper and no protection of airbags seems to be a common complaint found online. Positive feedback: the entire front end, engine, battery, etc. Compacted into a pancake, but the passenger compartment had only a small buckle on the floor board at the pedals. The engine was crushed. This was a definite positive. (unrelated to accident complaint above: the exterior handles of the sliding doors were replaced twice. Prior to the latter repair, when the passenger side exterior sliding door handle broke, my daughter's hand was cut and bruised!).

While driving too fast went down into a dip or up a driveway which caused bottom of vehicle to hit the ground. Please provide further information.