Alice agreed to buy Ben's car provided Ben made a certain modifications to the car's engine. Ben agreed and Alice gave Ben a deposit of 10 per cent of the purchase price. Ben made the modifications but, before he could inform Alice, the car was was already destroyed in a fire at Ben's garage.

Ben, who wa uninsured, is demanding that Aloce pay the agreed price for the car. Alice refuses to do this. She is demanding the return of her deposit and threating to sue Ben for non- delivery of the vehicle.

Advise the parties taking into account the principles of the law of sale.