OROVILLE, Calif. (AP) – An Associated Press review has uncovered a series of questionable decisions and missteps before and during a crisis at America’s tallest dam. In February, a massive crack opened in the main spillway at the Oroville Dam in Northern California. For days, managers assured the public there was no imminent danger as they slowed releases of water to assess the damage. Then, a backup spillway started falling apart, triggering an evacuation order for nearly 200,000 people. The AP has found the dam received an uncommon exemption from federal rules requiring it to release huge amounts of water. And government overseers overestimated the durability of the two spillways. State water officials say the crisis was managed as effectively as possible.