OREGON — Two years ago, on Labor Day evening, wildfires exploded across Oregon and brought a level of destruction never before witnessed in the state. Nine people were killed, including five in the Santiam Canyon, and thousands of homes and over a million acres burned. The causes of the wildfires have been debated ever since they ignited. Historically powerful east winds on Sept. 7 and 8 caused existing wildfires, including the Beachie Creek and Lionshead fires, to explode and quickly spread. The wind also brought down power lines in numerous locations statewide, likely igniting additional wildfires. Arson also has been investigated — and one person found guilty. But amid the reporting, debates and speculation, one key document has been missing: final investigation reports that lay out exactly how each firestorm ignited. …Two years later, of the 10 major Labor Day fires in Oregon, no investigations have been completed.