Worst case would be the comb all broke loose and honey oozing which would have most likely killed a large portion of the bees. There is not much you can do with that.
More likely is that most of the comb survived the fall (ie. branches cushioned the fall). If the tree has not split open exposing large portions of the comb, then if possible, I would leave in situ if at all possible and provide any needed protection to the entrance and close up any major holes. If the split has major comb exposure than a possible emergency cut-out is the only option. Anything in between, you have to use your judgement. If there is anyway to patch/repair the situation as is, that will give then the best chance. If you have to move the tree section, be as gentle as possible and don't roll any more than needed.
Good luck, let us know how it goes. Pictures are always helpful as well.