The National Transportation Safety Board has released a preliminary investigative report on a fatal helicopter crash that took place in Maplewood in June. The June 19th accident involved a mosquito-control helicopter owned by Scott’s Helicopter Services of Le Sueur, and killed the chopper’s pilot, 44-year-old Michael Kramer of St. Charles. The NTSB report says that witnesses saw the helicopter lose altitude, turn or roll to the left, and then descend, at which point they lost sight of it behind some houses. A GPS device onboard the aircraft was recovered and sent to Washington DC for data extraction. The NTSB says a flight plan was not filed.