LOS ANGELES—An explosion of unknown size and origin occurred Jan. 26 in a three-story science building on the USC campus, and one person was taken to a hospital for unspecified injuries.

The blast was reported at about 4 p.m. in the Neely Petroleum Building at 923 Bloom Walk, according to the Los Angeles Fire Department and USC Department of Public Safety.

Fire officials said one person walked out of the building after the blast and was evaluated at the scene and eventually taken to a hospital for treatment of unknown injuries.

The building was evacuated as a hazardous materials team was called to investigate the cause of the blast.

USC Department of Public Safety announced via Twitter that there was a gas leak at the building, but fire department officials could not immediately confirm that report.

A haz-mat team eventually searched the building and found no leaks or hazards, and all air readings were normal, according to the Los Angeles Fire Department. The building evacuation was lifted shortly after 5 p.m.