KANSAS CITY, Mo. -- Two Colorado dentists were identified Monday as the victims of a small plane crash in the Ozarks.

The Denver Post reported that Drs. Marty Bench and Doug Leonardson were identified by a brother of Leonardson.

The Piper Saratoga crashed Monday evening about five miles south of Kansas City International Airport and was on final approach when it went down, according to news reports. The Kansas City Star reported that the plane was coming from Osage Beach, Mo., and crashed in a soybean field.

Eyewitness Denver Briem told the Star that he heard a "loud boom, like a stick of dynamite," and saw the plane spiral to the ground.

"I looked up, and I could see debris in the sky. I saw part of a wing, and I could see a wing and fuselage spiraling down," witness Bob Kelly told KMBC.

Reporter Martin Augustine said that several pieces of the plane were scattered several hundred feet across the field, which indicated that the plane came apart in flight.

The National Transportation Safety Board sent an investigator to the crash site.

Bench was an oral surgeon and Leonardson was an endodontist and often vacationed together, according to the Post. They were the only people on board.