Pacific Western Mobile Estates, Inc. (Pacific) (defendant) acquired a trailer park with spaces for 143 trailers. The trailer park included a sewage treatment plant 200 yards away from the nearest trailer. The treatment plant had a settlement tank with dimensions resembling a swimming pool. The water in the tank was maintained at 1.5 feet below the rim, and there was no ladder. A bridge-like wooden contraption spanned the tank, as did a metal lattice. A six-foot-tall fence with locked gates surrounded the tank. No signs warned against entering the treatment plant. When Pacific acquired the trailer park, the previous owner removed 60 trailers. Each trailer had been supported with concrete blocks, which were left behind. Pacific’s employees stacked the abandoned concrete blocks against the wooden fence enclosing the tank, forming a staircase to the top of the fence. Pacific’s manager was aware that the children living in the trailer park played all over the premises. Mark Crawford lived in the trailer park with his family. He was six years old and knew how to swim. One day Mark and several other children were playing on the concrete blocks. The group of children called to an older child who was passing by and told him that a child was in the settlement tank. Only a children’s ball was visible floating on the surface. Mark’s father and a neighbor dragged the tank with a rake and pulled out Mark’s body. Mark’s parents (plaintiffs) sued Pacific and its manager for the wrongful death of their son. A jury found in favor of the Crawfords and awarded them $30,000 in damages. The trial court entered a judgment notwithstanding the verdict in favor of Pacific. The Crawfords appealed.