Japanese officials should have been better prepared for the earthquake that launched a nuclear crisis, an AP investigation shows: in preparing the Fukushima plant for natural disaster, scientists ignored thousands of years of history and dismissed mounds of important evidence. They calculated that the waves would rise only 18 feet and estimated that an earthquake could reach only a maximum 8.6 magnitude. They ignored Japan's geological history, excluding from their estimates a massive quake that occurred over 1,000 years ago. They also calculated the risk based on the past—the damage wrought by earthquakes since 1896—instead of preparing for the worst possible scenario as other experts advised. Scientists also downplayed the stress buildup occurring along the two tectonic plates that caused the 9.0-magnitude earthquake.