Scranton, PA – SCRANTON — A malfunctioning water heater in a University of Scranton freshman dormitory caused a build up of carbon monoxide in the building early Monday morning, leading to an evacuation of the hall’s students, two of whom were briefly hospitalized, a university spokesman said.

About midnight, university police noticed an unexplained smell in Martin Hall during a patrol and city firefighters found an abnormal level of carbon monoxide, spokesman Stan Zygmunt said in an email.

Crews ventilated the building and activated a backup water heater. Affected students received temporary housing until the hall was cleared at 9 a.m. Students were evaluated and two, who were not identified, were taken to a hospital, where they were treated and released.