I am a junior at a University in the San Francisco Bay Area. For the past three days there have been very loud/violent sounds coming from the roof (I live on the top/3rd floor). The building shakes for about 30 seconds while the sound happens. It sounds like a GIANT suitcase rolling back and forth or a VERY VERY big and loud sewing machine.
Any Ideas or comments about this bizarre situation? It has been happening every 15 minutes this morning from 6:45am to now....8:45am.