Steve, a driver for QRI, leaves the truck's motor running in neutral and carelessly forgets to set the parking brake while he makes a delivery. The truck rolls and crashes into a nearby gas station pump, igniting a fire that spreads quickly to a construction site a block away. A burned wall collapses onto a crane, which falls on, and injures, a bystander, Helen. What must Helen show to recover damages from Steve? What are QRIs potential liabilities?