Update: McCord Hall fire ruled accidental, electrical in nature

The structure fire at McCord Hall on the University of Tennessee agricultural campus was accidental, according to arson investigators.

Authorities said water from the third floor leaked down into an overhead light in a laboratory. That caused an electrical short, which started the fire.

Previous report: McCord Hall fire put out

Knoxville firefighters have extinguished the fire at McCord Hall on the University of Tennessee agricultural campus.

The fire call came in at 2:20 p.m. Monday according to dispatchers.

A University of Tennessee spokesperson said the fire appears to have started in one of the laboratories on the first and second floors, near the loading docks.

Two people were inside, but they evacuated without injury.

There is extensive smoke and water damage on the scene.

University of Tennessee Agricultural Extension Agent Neal Denton described McCord Hall as the university's old dairy facility.

Denton says the building contains Mabel's restaurant, which is still open during the school year, as well as offices and some old laboratories.

One of those laboratories presented a safety concern for firefighters, as it houses several chemicals and bacteria. Room 57 contained samples of salmonella, campylobacter, and e. coli, and was next door to Room 56, where the fire was located.

While the bacteria are not airborne threats, they could create a problem if they came in contact with an open cut, the nose, or the mouth. Firefighters cleaned their gear after extinguishing the fire, as a precaution.