Mining gold with it...gee, I wish that was the reason it was stolen, but somehow, I think not.
I wonder if the Egyptians who fell ill were Coptic Christians?? If a muslim wanted to do a test-run, a Christian who fled from muslim persecution in Egypt would certainly be a choice target for islamics.
In my city, we have about 1 hundred Coptic Christians who fled muslim persecution a few years ago. Their villages were raided and their clergy was butchered.