Independent experts have preliminarily identified dozens of possible causes of this winter's spillway crisis at California's Oroville Dam.

California released preliminary findings Wednesday from a team appointed to find out why both spillways at the nation's tallest dam collapsed in February. The crisis forced the evacuation of nearly 200,000 people.

The experts say possible factors include a range of flaws in the concrete and foundation of the half-century-old main spillway. That includes possible water flows through cracks in the spillway.

The independent experts' final findings on the causes of the crisis at Oroville Dam are expected to be released next fall. Authorities say the preliminary findings will guide them as they repair the battered spillways.