The business jet was destroyed when it impacted terrain at 0955 Mountain time during takeoff from the Montrose Regional Airport in Montrose, Colo. The captain, flight attendant and one passenger were fatally injured. The first officer, and two passengers sustained serious injuries. Instrument conditions prevailed. The airplane arrived around 0900 and dropped off a passenger. After remaining at the FBO for about 50 minutes, the airplane was boarded and taxied onto Runway 31 where it performed a static run-up for approximately one minute. Subsequently, the initial ground roll appeared to be uneventful. Several witnesses reported hearing a loud boom or whooshing. The airplane was observed in a yaw to the right, putting the tail of the airplane perpendicular to the runway. The airplane impacted terrain to the right of runway and slid approximately 1400 feet, through the airport perimeter fence, across a road and through an adjacent fence. Reported weather included calm winds, a visibility of 1 miles in light snow and mist, a few clouds at 500 feet agl, an overcast at 900 feet agl, a temperature of -1 Celsius and a dewpoint of -2 C.