"The vehicle suffered a critical failure of the shift interlock safety system. After parking in a driveway, the ignition key was able to be fully turned to the 'off' position and removed from the ignition cylinder, even though the transmission was not successfully secured in 'Park.' After the key was removed and I and went into the house the van rolled away. It traveled downhill, crashed through a fence, and collided with a residential structure, causing significant property damage to the house and vehicle. This failure could potentially cause serious injury or death and this was the first time that it had occurred and is exhibiting the same failure as described. Immediately following the collision, video evidence was recorded showing the key in hand while the dashboard indicators and shifter remained out of the 'Park' position. This indicates the safety mechanism designed to prevent key removal unless the vehicle is in 'Park' failed to operate, creating a life-safety rollaway hazard."