A residence hall on the campus of University was evacuated after a number of student residents became seriously ill from aerial dispersal of bacteria that had infested the air conditioning system. Reputable consultants retained by University to prescribe a remedy for the infestation advised University that there were three ways to proceed: the cheapest would be to purge the air conditioning system with disinfectants, which had usually taken care of the problem in several other similar circumstances; a more expensive method would be to seal off and fumigate the building, which would be more effective; and the most expensive, and the most effective, would be to do multiple sealed fumigations.

To minimize the expense, University chose the cheapest method. University was also motivated by the need to recover revenues that it had lost during the closure and by the need to be able to provide desperately needed housing for the students. After allowing time for the disinfectant to work its way out of the air conditioning system, University reopened the residence hall and advertised reduced rates to induce students to move back in.

Paula and her roommate Art, students attracted by the reduced rates, spoke with University's Director of Student Housing, who told them that it was safe to move back. Paula said, "Well, I guess I have to rely on your judgment." Art agreed, saying, "At that price, it's worth the risk." They resumed living in the residence hall. Soon after they moved back, Paula and Art had an argument, which left Paula harboring anger against Art.

Within a month, Paula fell ill with the same bacterial infection. Art did not become ill. However, while waiting for an ambulance to pick her up, Paula stuffed Art's pillow into the ventilator duct with the intent of allowing the pillow to accumulate as much bacteria as possible. She then placed the pillow on Art's bed. A week later, Art became ill with the same infection.

Paula and Art each wish to sue University for personal injury. What theory of liability should they assert, what defenses might University raise against each, and who would be likely to prevail in each suit? Discuss