Jack Bonner, 15, said he was hanging out at his home near the airport with a friend when he heard a boom "like a thunderclap."
"I was like, 'Wow, what the heck is going on?'" he told the Los Angeles Times, before turning on the TV and learning about the plane.
The jet, a Cessna 525A manufactured in 2003, is registered to a Malibu, Calif. address and its corporate owner, Creative Real Estate Exchange, is based in Birmingham, Ala., and Atlanta, according to FAA public records.
Phone messages left after hours at the real estate company's two offices were not immediately returned.
The National Transportation Safety Board would take over the investigation as is routine in such crashes.
Santa Monica Airport, located in the coastal tourist destination known for its trendy bars, restaurants and wooden-pier carnival, is home to many private jets, many of them used by wealthy Southern Californians from the entertainment industry.
The airport in Hailey serves Idaho's Sun Valley resort area, which is a frequent destination for many celebrities, and the rich and powerful alike.