Marlin -

You are right that the expected number of fatalities would be 0.4. Obviously, there is no such thing as 0.4 fatalities. There have to be zero, one, two, etc. fatalities. Each number of fatalities has a probability associated with it. Based on my assumptions, the probability of zero fatalities was 82%. Since all probabilities have to sum to 100%, the probability of a number of fatalities greater than zero was 18%.