Titan Tire of Natchez officials are trying to determine what caused a fire that seriously burned two employees early Monday.

“All I can tell you is we’re investigating the causes,” said plant manager Dave Fines, who would not comment further.

Paul Baxter and Marcella Robinson, ages and addresses unavailable, were burned in the apparent explosion and fire on the No. 1 banbury unit, according to Natchez Fire Department reports.

Robinson was in stable condition at Natchez Regional Medical Center’s intensive care unit late Monday, suffering from a combination of burns on his body, a nursing supervisor said.

Baxter, whom paramedics said received second and third degree burns, was in fair condition when transferred from Natchez Community Hospital to a specialized burn center. A hospital spokesperson said the family requested that no information be released.

Fire Chief Gary Winborne said the fire and explosion occurred when a banbury &110; the machine used for mixing raw, melted rubber and carbon black dust to create the material used in making tires &110; apparently “kind of burped or regurgitated, and dust flew up everywhere.”

“What actually ignited the dust, they don’t know,” he added.

And what caused that “fairly unusual”&160;fire is what Titan plant engineers are trying to determine, said Phil Stanhope, a Titan spokesman.

“It’s fairly unusual that this would happen,” said Phil Stanhope, a Titan spokesman. “This material wouldn’t normally flashover.”

Stanhope said that while it is not unusual for a banbury to regurgitate carbon black, “this is the first time they’ve ever ever seen that happen in that plant.”

Winborne said the banbury had been out of production for about three months and had just started mixing batches of carbon black and rubber again at 7 a.m. Monday.

“But they’d been having problems with it that morning,” he said, adding that the company reported a problem with the dust collector on the first batch processed. During the second batch, the operators discovered a computer problem, which was corrected.

After about five batches had been run, carbon black &110; one of the main ingredients in the process &110; regurgitated for the first time, covering the area in carbon black.

Winborne said the company reports indicate employees cleaned the area and restarted the banbury again at about 8:50 a.m.

Shortly after 9 a.m., witnesses reported seeing another cloud of carbon black come from the banbury and then ignite in the flash fire, Winborne said.

That fire caught Baxter’s and Robinson’s clothes on fire, Winborne said.

“It also set some of the material on the machine on fire” activating the sprinkler system, which extinguished the fire on the banbury, Winborne said.

Winborne said the fire was out by the time firefighters arrived and Fines reported that the banbury had been shut down immediately. And, Winborne said, according to company reports the banbury was not hot at the time of the fire nor was the rubber above it, in what is called a “drop mill.”

Winborne said that although static electricity could have caused a spark and fire, the machines are supposed to be wired to prevent static electricity from building up.

Stanhope said he would not speculate on the possible causes of the fire.

However, the company maintains that normal procedure for a banbury start-up was followed. Robinson has been a Titan employee for more than year and Baxter has worked with the company for about three months, Fines said. Fines said the company will follow the law in reporting the incident to OSHA. However, he said that his understanding of the law is that an incident must be reported within 48 hours only if it involves a fatality or three or more injuries.