Not good. Wonder how 6 people were injured?
When it derailed then it will stop abruptly and people getting on could be hit by the approaching empty chair swinging violently. Everyone on the chair should have been fine(edit: fingers crossed safety bars were all down) and although a traumatic experience they probably got harnessed in and lowered off the chairs, a long and drawn out process which maybe resulted in mild hypothermia depending on the conditions.
Support goes out to everyone involved and those in the operation to get people back on the ground and into the warmth.