Preliminary FAA and NTSB information says the plane was attempting a go-around when its left wing dipped; it appeared to stall, spin into the ground and ignite.
Video from the scene showed thick black smoke rising from the wreckage, and San Diego fire crews said the aircraft was so badly damaged they could not extract the victims before focusing on the flames.
The NTSB is leading the investigation, with an investigator sent to document the crash site before the aircraft is moved to a secure facility for further examination.