Tulsa School of Arts and Sciences fire ruled accidental, resulted from construction

TULSA - The investigation into the massive fire that destroyed Tulsa School of Arts and Sciences last Wednesday is complete and the fire has been ruled accidental.

Investigators from the Tulsa Fire Department and the Bureau of Alcohol, Tobacco, Firearms and Explosives determined the fire was accidental, resulting from construction related to the installation of an exhaust vent in the lab area.

View pictures from the scene at http:// bit.ly/ ThWi2Q .

The investigation also determined the explosions that occurred, injuring eight firefighters, were caused when oxygen was introduced into the area by the firefighters entering the room to extinguish the fire.

Officials say the fire was smoldering in the void between the chemistry lab ceiling and the floor of the room and hallway above.  The fire migrated north under the hallway floor into the classroom and the crawl space below where it vented from the classroom window.

Officials say the resulting smoke explosion, or back draft, occurred when the firefighters entered the area.

A second, larger explosive occurred four seconds later when the hot gas layer accumulated between the drop ceiling and the roof.  Officials say this was caused by the turbulent and sudden change in the environment as a result of the explosion.

The TSAS building, which was formerly Barnard Elementary School, was equipped with three smoke detectors, but officials say the nature of the fire and the location were not sufficient to activate the alarms.

Upon completion of the investigation, Tulsa Public Schools' Superintendent Dr. Keith Ballard released the following statement:

We are so appreciative of the hard work of the Tulsa Fire Department and the ATF in bringing this investigation to a conclusion.  We remain concerned about the safety and welfare of the eight firefighters who were injured in the blaze, and our hearts go out to them and their families.  Without a doubt, we are privileged in Tulsa to be served by such fine men and women as those serving with the Tulsa Fire Department.  The district continues to explore its options with the Barnard property and we are still in information-gathering mode, working in conjunction with TSAS and our insurance companies.  In the coming weeks, the TPS board will make a decision as to how we will proceed with the property.