Oskar, the market gardener had a reputation for growing organic potatoes in the village. Ursula, a gourmet cook, wanted to purchase 2 kilograms of organic potatoes at the market garden. Oskar said that he would wash, weigh and package the potatoes and that Ursula could return and pick them up when she had completed her shopping. Ursula paid Oskar the $ 20 price before she left. While Ursula was shopping, a truck, owned by Norbert, backed into Oskar's market garden stall, destroying 100% of his vegetables. At the time of the accident, the potatoes had not been washed, weighed and packaged.

Who owns the potatoes? Why? Define and explain any legal concept you use.