Hazmat crews responded to a strange odor reported at a University City biomedical research building after a water leak.
The Philadelphia Fire Department said officials were called to the Wistar Institute on the 3600 block of Spruce Street just after 7:45 a.m.
An unusual odor was reported in the air in the building on the University of Pennsylvania campus, the fire department said. No one was reported to have become sick from the smell.
A Wistar spokeswoman said the odor appears to have been caused by a water leak that occurred further east on Spruce Street and affected the building's steam pipes.
Workers are continuing to examine Wistar's steam lines, though no leaks there were immediately apparent.