Why should the station be held responsible for not knowing water could kill you, when the woman didn't know either?
During the show, a nurse called in and warned them about the danger and was blown off by the on-air staff.
Even though she died at home, the toxic dose was clearly given on the station's property. Get it? On the station's property.
Factor the above into the equation. Also factor that she's got children.
Also factor that this is California, the most litigious state in the nation.
I repeat, the station's toast.
They're responsible. Holding the contest means they assumed an obligation to check out the risks. This is particularly true for contests where contestants are pitted against each other in endurance type situations (staying awake contests, etc.) IIRC, one station had a contest where contestants had to keep touching a new car, and the last person touching it won. They gave the people bathroom breaks every couple of hours, but also kept a doctor on site for the entire duration, since they were there for several days.