TAVARES, Fla. -Investigators working to find the cause of the explosions at the Blue Rhino plant in Tavares said they will focus on the back of the building on Thursday.

The Bureau of Alcohol, Tobacco and Firearms and Explosives began its investigation on Wednesday saying it was in the initial stages.

Tavares Fire Chief Richard Keith said he believed it was the combination of human error and equipment failure that caused the blasts, but Brown said it's too early to make that call.

"I don't have all the information right now to make that determination. We don't make that determination until we're finished with the investigation," said Brown.

It does not appear anyone intentionally caused the explosions.

The Leesburg Daily Commercial reports that a maintenance worker named Gene Williams said he rescued a forklift operator with burns on his hands and face, right near the spot where the first explosion and fire occurred.

Investigators also said surveillance cameras did not capture whatever ignited the tanks.

ATF, OSHA and the fire marshal have set up command trailers to be able to continue their investigations, which could take weeks.

There were 25 to 30 workers on the property at Blue Rhino, a division of FerrellGas, at the time of the explosions.