BORREGO SPRINGS, Calif. -- An investigation was underway Friday into a light plane crash that killed one person near a desert airstrip in the far northeastern reaches of San Diego County, according to authorities.

The crash was reported about a mile north of Borrego Valley Airport after 1 p.m. Thursday, said San Diego County sheriff's Lt. Anthony Ray.

The pilot died at the scene, he said.

The pilot was practicing for a Borrego Springs air show in his personally assembled plane at the time of the crash, according to the San Diego County Medical Examiner's Office.

Moments before the crash, the man reportedly called a friend and stated that his stick had broken. The friend then watched as the man's plane suddenly dived and crash into the ground, the Medical Examiner's Office reported.

According to Federal Aviation Administration records, the plane, a single engine, experimental Harmon Rocket, was registered to Van Snow of Santa Ynez in Santa Barbara County. The county coroner's office did not immediately confirm the pilot's name.

The National Transportation Safety Board and the FAA were investigating.