Pipe.

This morning I woke up and a friend had texted me and it was -17 degrees Fahrenheit out, and like an hour-and-half into translating Greek over breakfast, water just started pouring down outside my window and it wasn't letting up, so I called the janitor in case an external pipe of some sort had burst (there's something going up past my window somehow).

Anyhow, he came and checked, and he thinks it was just water that had accumulated on the roof next to a steam pipe, and had at last somehow started to pour off the roof and he told me not to worry, which was right, since by the time I finally left for school the water had stopped coming down.