I think Trees, you need more complex molecules than simple water. This is something I've thought about since buying my first microwave over 20 years ago.
Back then the there was the story (urban myth?) that microwaving an egg could blow the door off the oven. Why would they do that? Possibly they put the egg in a glass of water to boil it for 3 mins. But clean water doesn't react to microwaves the way complex proteins do, so maybe the water stays cool while the egg overheats within the shell and "blows"?
I'm not putting this forward as "fact" merely possibility.
