1.   The fire prevented the rescue of any of the badly hurt victims.

2.   The glare from the sun had shielded their eyesight and perhaps prevented his rescue.

3.   Crews got a break late Wednesday from snow and poor visibility that had prevented rescue of the four climbers and five national park rangers.

4.   Many doors of the building were locked, preventing quick rescue.

5.   Authorities say the overheated debris so far prevented rescue of the bodies or clean-up of the wreck.