Car Accelerates On Its Own problems of the 2006 Infiniti M45

I was driving a 2006 Infiniti M45. I was pulling into a parking place. I had my foot on the brake. The car was slowing to a stop and had stopped forward motion. I was getting ready to stop the engine. Suddenly with my foot still on the brake the vehicle surged forward, jumped the concrete parking barracde and then proceeded over the curb, down a 3 foot drop crashing into the ground and then hitting the corner of a brick condominium. There was no injury. I was alone in the vehicle. No air bag deployed. I did have my seat belt on. My brother witnessed the event as did the lawyer I was coming to see. My foot was on the brake the entire time during the incident. My foot was still on the brake when the car finally stopped. I have no explanation for the sudden acceleration. The vehicle is currently being repaired. There is front end damage and undercarriage damage from the sudden acceleration fall and crash.