LOS ANGELES (CBS) — A hazardous chemicals spill at a University of Southern California campus prompted evacuations and road closures, according to the L.A. City Fire Department.

Workers reportedly spilled large amounts of a chemical which they feared was radioactive in a pathology reference laboratory, located at 2250 East Alcazar Street. The building is located on the Health Sciences Campus, which is a 15-minute drive from the main USC campus.

Employees were tested and all showed negative for radioactivity. No injuries or illnesses were reported.

The first floor was reopened just before 5 p.m. but the second floor remained closed.

An investigation was underway.