CHAMBERLAIN -- Representatives from federal and state agencies gathered Monday afternoon in Chamberlain to begin investigating a plane crash that left nine dead and three wounded Saturday afternoon.

Representatives from the state, including an officer from the South Dakota Office of Homeland Security, arrived at about noon on Monday to examine what remained of the plane, which crashed into a cornfield on a property off 342nd Avenue and about a mile north of the Chamberlain Municipal Airport. They left about 1 p.m. to convene with other authorities at the airport before heading back to the scene.

A representative from the National Transportation Safety Board told The Daily Republic on Monday outside the airport that investigation at the scene will likely last several days and will involve NTSB, state homeland security, the Federal Aviation Administration and a representative from Pilatus Aircraft Ltd., the company that manufactured the plane.

According to an NTSB statement released Monday afternoon, the three NTSB investigators who arrived in Chamberlain Monday after being delayed by weather will spend the next several days documenting the plane's wreckage, systems, flight controls and engines and will be interviewing those who witnessed the crash and potentially the three surviving passengers.

According to the NTSB, the crash occurred at about 12:30 p.m. Saturday. At about 9:30 a.m. Friday, the plane's 12 occupants had arrived in Chamberlain for a pheasant hunting trip. The pilot, whose name has not been released, purchased 150 gallons of Jet A fuel from an automatic fuel pump shortly after arrival and was parked on the airport ramp between arrival and the departure that ended with the crash.

The FAA had given the pilot clearance to fly Saturday, with a 12:20 p.m. scheduled departure for Idaho Falls, Idaho. The plane reportedly departed Chamberlain's runway 31 at 12:26 p.m., and the FAA issued an alert for a missing plane when the flight plan was not activated.

The NTSB report says weather conditions were a half-mile visibility with moderate snow and icing, low-level windshear, and clear air turbulence conditions with overcast skies.

Identities of the 12 people on board the Pilatus PC-12 have not been officially confirmed, though all are said to be from Idaho and many were related. A winter storm was in progress when the crash occurred and impeded inspection of the crash, though all bodies were removed from the cornfield by Saturday afternoon.

Brule County Emergency Manager Kathryn Benton said the people on the plane ranged in age from 7 to 81, and two of those who were killed were children. Men ages 17, 27 and 28 survived the crash and were taken to the Sioux Falls area for injuries sustained in the crash.

Investigators will be searching for equipment on the plane that could have relevant information, though the Pilatus PC-12 is not required to have a cockpit voice recorder or flight data recorder. The plane was reportedly equipped with a system that records parameters such as flight track, altitude and speed during the flight.

The NTSB expects a report with information gathered in the early stages of the investigation will be released within two weeks, while a full investigation determining the probable cause of the crash and its contributing factors will take 12 to 24 months to complete.

The owner of the property where the plane crashed declined to provide additional information about the crash to The Daily Republic on Monday.

Brule County State's Attorney Theresa Maule Rossow and the Missouri Valley Ambulance Service had not responded to messages from The Daily Republic to provide additional information about the crash as of Monday afternoon.