I certainly feel for you. To lose those images, and the quality with which they would have been taken if they survived is simply heartbreaking, but I'm certain that other people at the reception took pictures. I would suggest combing through those images to find duplicates of the missing ones. That way you'll at least have photos of those dances, even though not from your photographer.

I would also suggest looking through your contract and all other paperwork regarding your agreement with the photographer. There's very likely something in there to address lost images.

If you can find acceptable images that were taken by your guests, take the negatives to your photographer and ask him if he could have them enlarged and printed at his cost to make up for the ones that were corrupted. If I were the photographer, I would gladly do this to keep a customer happy rather than risk negative word of mouth.

Try not to be confrontational about it; be understanding. Approach from the standpoint of, "I know things can happen sometimes, but let's try to make the best of it. Could you enlarge and print these other images to make up for the ones that were lost?"

He should be glad to do it in order to keep a customer happy. Wedding photographers rely on word of mouth advertising more than any other kind. If he doesn't care, or doesn't offer some kind of solution, then eventually he'll put himself out of business, I've seen it happen to photographers in my area.

I hope I've helped out a little. I know it's not a lot, and probably not what you wanted to hear, but it's an impartial opinion on how best to handle the situation.