Kenneth Corson, 10, lived with his mother, Lynda Lontz, in an apartment building owned by Bruno and Carolyn Kosinski. While playing with other children who lived in the same building, Corson was drawn to a stairwell that provided access to the building’s laundry room and roof. Corson and the other children climbed to the roof and discovered an area where they could jump from the roof of their building to that of the building next door. The children engaged in roof-hopping for several days. On the last day, Corson misjudged his jump and fell the three stories to the ground below. Corson and his mother filed suit against the Kosinskis to collect damages for Corson’s injuries. What theory might be used to hold the Kosinskis liable? [Corson by Lontz v. Kosinski, 801 F. Supp. 75 (N.D. Ill.)]