Firefighters could only watch as a pet food company building continued to burn through its fourth day Monday.
"We have crews on scene, but they're not able to do active firefighting," Capt. Stuart Bevis of the Wichita Fire Department said. "They're only able to put water on the fire... from a distance."
The four-story shipping and packing area of the TreatCo plant appeared like a smokestack with windows, creating a haze over the area near Broadway and 21st Street.
The fire, which began Thursday and appeared to ignite again Friday, left firefighters wondering when it might burn itself out.
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"We don't have a clue," Bevis said. "We're just in a holding pattern. We still have some significant fire."
Four fire engines sat nearby as pallets of dog treats burned, and concern lingered about chemicals and acid inside the structure.
"The firefighting has to be done very carefully," Bevis said.
There was no sprinkler system in the building, which dated to the 1890s and held large amounts of animal fat and packing materials.
"Basically, we have a huge concrete box full of fuel. That just makes it a nightmare," Bevis said.
The plant produces about 2 million pounds of animal treats each month in its 750,000-square-foot processing plant, according to the company's website.
The city granted TreatCo permission to shut down its sprinkler system to a portion of its operations several years ago, Bevis said. He didn't know whether that's the same area now on fire.
Fire Marshal Brad Crisp is investigating the lack of a working sprinkler system.
The fire started in the pig ear drying section of the plant. Investigators haven't been able to get into the building to begin searching for a possible cause, Bevis said.
Police arrested siblings who are listed as co-owners of the company late Thursday night on suspicion of obstructing firefighters and battery of a law enforcement officer.
"It doesn't matter what the intentions are ... unless you're working with us and we're going in with you," Bevis said. "We have to coordinate that."
One co-owner had been "interfering with fire crews the whole time," Bevis said.
Firefighters had been worried the owners would get hurt by falling equipment.
"They can't do their jobs if they're worrying about somebody getting crushed," Bevis said.
By Monday, firefighters had been escorting employees to offices to retrieve computers and other equipment.
The initial fire call came in at 8:15 p.m. Thursday at the plant, 2302 N. Broadway.
It quickly grew to a three-alarm fire.
"We had pretty heavy fire that evening, had crews there all night," Bevis said.
When they returned Friday morning to mop up, they discovered a fire in another part of the complex.
Investigators aren't sure how the fire spread.
"It's extremely possible that it was just a normal progression of the fire," Bevis said.