Helicopters are notoriously hard to maneuver, and hence pilot error is a major reason in many helicopter crashes. Also, if a plane loses power, it still has time to glide down an make an emergency landing in many situations. If a helicopter loses power, it plummets to the ground and its occupants have zero chance of survival (with the Leicester owner for example). Finally, helicopters fly at much lower altitudes which make them more susceptible to colliding with high terrain and other obstacles. It looks like this is what happened in this case.