FARMVILLE — Longwood University is investigating an alleged sexual assault that reportedly took place Saturday morning. According to an email sent to Longwood students Tuesday afternoon, the assault took place in an on-campus residence hall. Director of Communications and Media Relations Matt McWilliams said the report was filed Tuesday and the investigation is ongoing by both the Longwood University Police Department and the Longwood Title IX office. “The university is obligated by (law) to send out a timely warning to the campus community,” McWilliams said, which the university did Tuesday, but could not comment on the incident as the investigation is ongoing.