A commuter plane that crashed last year into sea ice off Alaska, killing all 10 people on board, went down following a fatal combination of pilot error and safety breaches, according to a report by the National Transportation Safety Board. The plane was overweight for a trip into icy conditions, and the pilot was not monitoring and maintaining adequate airspeed, likely because he was trying to manage the plane’s ice protection system while preparing to approach Nome, Alaska. The Nome airport had temporarily closed its runways for de-icing. The NTSB found that the plane’s operator, Bering Air, had a history of overweight flights, with investigators finding a pattern of underreported weights on the flight manifests. NTSB chair Jennifer Homendy said in a statement that the tragedy “was not the result of a single failure, but a series of preventable breakdowns that eroded critical safety margins.”