A group of geologists is warning that it's not a matter of ” if” but rather “when”  a potentially devastating earthquake will strike Idaho. Geologist Bill Phillips with the Idaho Geological Survey, says his group  is predicting the next big one could hit within 50 years. Idaho's geology is dramatically different than that of Japan, so it wouldn't be as large but that such a quake would definitely impact Idaho. Phillips says the predicted quake could lead to a failure in infrastructure like dams and roads. Phillips says Idaho is behind in its building code regulations, which could make a difference between life and death.   A 6.9 earthquake hit the Mackay-Challis area in October of 1983 and killed two people.