The wreckage from a small plane crash in Idaho that killed a family of four from California was so badly burned that authorities were able to recover only a wingtip and the engine, federal transportation safety officials said Monday.

Family members identified the victims of the plane crash as 42-year-old Randy Whittle, his wife Vicki, 46, and their children, 16-year-old MacLean and 13-year-old Brittany, all of Claremont, Calif., according to a statement released by Idaho authorities.

Whittle had been a pilot for about five years and he and his family were in Idaho visiting his parents, said his brother, Dave Whittle of Springville, Utah.

The plane went down Sunday afternoon near the runway at the Burley airport in south-central Idaho. It is believed to have crashed immediately after taking off and clearing the 4,000-foot runway, according to the Federal Aviation Administration.

"My parents were at the airport and saw the crash," Dave Whittle told the Salt Lake Tribune.

The plane was headed to Provo, Utah, he said.

The plane is believed to have been a Cessna 210 based on the type of engine and number of propellers, said Jeff Rich, chief of the western pacific region for the National Transportation Safety Board.

"It's burned down to ash. Even identification of the aircraft was based on some circumstantial evidence," Rich told The Associated Press. "There's nothing left but a wingtip and the engine."

Saint Woodbury, a witness, told KMVT-TV he was on his way to the boat docks by the Burley Golf Course on Sunday when he saw a plume of smoke.

"At first I just thought it was a grass fire," Woodbury said. "But it was kind of weird because it was really dark, black smoke coming from there. And as I got ... closer, then I started to see part of a wing was actually laying on top of the railroad track. And that's when it actually dawned on me what was going on."

The NTSB sent an investigator to Burley on Monday to investigate the cause of the crash.

The Times-News reports that the fire ignited dry grass south of U.S. Highway 30. Burley firefighters responded to douse the flames.

A portion of U.S. Highway 30 was closed Monday while the crash was being investigated.