Ken Larsen's web site - MIT snow making hoax
MIT students have been known to pull some crazy pranks. This snow making prank occurred at my dormitory [Baker House] while I lived there as an undergraduate. I was not personally involved, but I saw the aftermath and heard the perpetrators tell the story.
The actual story was that there was a heavy snowstorm, and some members of my dormitory wanted to have a snowball fight ... but not outdoors ... where it was cold. Instead, they took a trashcan outside and filled it with snow. They brought their trashcan indoors and had a snowball fight in the corridor of one of the floors. After they finished, they had a lot of snow left over, so they hauled it to the bathroom showers. They dumped the snow on the floor of one of the shower stalls and then turned on the hot water to melt it. That created an enormous amount of steam. To try to get rid of the steam, they opened a small window at the top of the shower. That didn't work well, because the window was too small. Then, someone got the bright idea to call the local newspaper and tell them "We made snow." A gullible reporter showed up, and the story appeared the next day on page 1.
Wire services picked up the story, and it spread as far west as Chicago. Then, some school in Chicago tried to replicate the experiment ... without success ... and that caused the hoax to be exposed. The Boston newspaper printed a retraction and confessed that they had been duped.