If there's a bright side to look on (apart from the fact that all survived), it's that in such cases there are usually salvageable parts that go on to keep other examples flying or to complete static exhibits.
One of the saddest documentaries I remember concerned the restoration of a B-29 somewhere in the Arctic Circle. After many problems getting it airworthy it was ready to fly out when a relatively minor fuel leak caused a major fire and the aircraft's total destruction. Unfortunately aluminium burns rather well in the right circumstances, as the British Navy discovered in the Falklands War.