At approximately 1100 mountain time, a Piper PA-34-200T crashed in cruise flight near Alpine. The pilot and passenger were killed. The flight was IFR from Cal Black Memorial Airport to Provo Municipal Airport. After breaking out into VFR conditions, the pilot cancelled the IFR flight plan and proceeded under VFR to Salt Lake City Municipal Airport #2. Witnesses saw the airplane flying at 500 to 1,000 feet agl until it disappeared into a fog-shrouded area of higher terrain.