Washington (CNN) -- The pilot of the P-51 Mustang that crashed at the Reno Air Races last September experienced overwhelming g-forces at the outset of the incident, and likely was incapacitated almost instantly, the National Transportation Safety Board said Tuesday.

CNN: NTSB: Pilot overwhelmed by g-forces in Reno crash

Two of the five crew members died, including the pilot, Major Ployer P.

NEWYORKER: The Checklist

The pilot of the Cessna 210 declared an emergency for unknown reasons around 6:10 p.m. shortly after leaving Santa Monica Airport, according to Ian Gregor, a spokesman with the Federal Aviation Administration in its Western-Pacific region.

CNN: 1 killed after plane crashes in Los Angeles neighborhood