PHILADELPHIA (CBS) – Officials now say a steam leak inside a University of Pennsylvania building caused the fumes that sent one person to the hospital.

There was apparently a leak in the basement of the six-story Wistar Institute, located at 3600 Spruce Street on Penn’s Campus, which officials say caused fumes throughout the facility.

One person was taken to the Hospital of the University of Pennsylvania after experiencing a reaction to those fumes. There is no word on that person’s condition.

The facility’s website describes the Wistar Institute as an “international leader in basic biomedical research.”