Ruth carelessly parks her car on a steep hill, leaves the car in

Ruth carelessly parks her car on a steep hill, leaves the car in neutral, and fails to engage the parking  brake. The car rolls down the hill and knocks down a power line. The sparks from the broken line ignite a grass fire. The fire spreads until it reaches a barn one mile away. The barn houses dynamite, and teh burning barn explodes, causing part of the roof to fall on and injure Jim, a psssing motoirist.  Which element of negligence is of the geatest concenr here? What legal doctrine resolves this issue? Will Jim be able to recover damages from  Ruth? Explain fully. 

Ruth carelessly parks her car on a steep hill, leaves the car in neutral, and fails to engage the parking  brake. The car rolls down the hill and knocks down a power line. The sparks from the broken line ignite a grass fire. The fire spreads until it reaches a barn one mile away. The barn houses dynamite, and teh burning barn explodes, causing part of the roof to fall on and injure Jim, a psssing motoirist.  Which element of negligence is of the geatest concenr here? What legal doctrine resolves this issue? Will Jim be able to recover damages from  Ruth? Explain fully.