That was American Airlines Flight 587. It crashed shortly after takeoff when it encountered the vortices from a JAL 747. It appears the copilot (who was flying at the time) either overcontrolled the rudder and overstressed the system or that the control system malfunctioned. The vertical stabilizer and rudder ripped off the plane, causing it to lose control. The lateral g forces were stronger than the engine pylons could handle, so both engines came off the plane before impact.

As for the Wellstone crash, it's proving difficult to investigate. There was no cockpit voice or flight data recorder on the plane and it burned on impact. The primary runway (9/27) runs east and west but the crash was well to the south. This corresponds to what might happen if the pilot executed a missed approach. I've checked all 4 of the instrument approach procedures for that airport and 3 of them call for a turn to the south in the event of a missed approach. A CNN article yesterday said that the plane hit the ground at about a 25 degree nose down angle.

There was reduced visibility, low ceilings, and light snow with icing at the time of the accident. Perhaps the deicing system malfunctioned or wasn't used properly. It's really hard to tell. If the deicers on the horizontal stabilizer failed, the pilot would have a hard time with pitch control. That might explain the nose down impact.