TYLER, TX (KLTV) - Three fire departments responded to Tyler Pipe after a fire broke out in an air filtration unit July 12. It happened near the middle of the plant which is located at Highway 69 and Ann Campbell Road. The filtration unit, also known as a bag house, was superheated beyond the capabilities of Tyler Pipe employees to handle. We were first on the scene, and after the fire, sat down with Captain Bobby Wallert of the Lindale Fire Department. Red Springs, Lindale, and Dixie Fire Departments responded to a call of a burning Popular Bag house. "The bag house is a filtering system for any air that's coming outside the foundry. It was all lit off in a duct into the bag house which is a contained building, " said Greg Simmons, Assistant General Manager of Tyler Pipe. Simmons said there were no employees in the area when the fire started because the bag house is unmanned. Captain Bobby Wallert responded with the Lindale Fire Department. "The fire was inside here. There's actually a little level here, and near the top and down there are some four-foot canisters that caught on fire. All this was burning, all this was open with smoke when we arrived, and we opened the door on the back so we could see through the whole thing. We didn't see any fire when we opened the doors. Once we took a temperature reading it tacked the gun out, so I'm guessing around 2, 000 degrees inside. We got to see the middle was orange, it was glowing on the inside .Mulberry Holdalls. It was that hot, " Captain Wallert said, pointing at the bag house which is about the size of a small silo. "We did have a Red Springs firefighter in the beginning who was complaining of difficulty breathing; it appears he has been sick throughout the weekend and the week. EMS was called for him. He was checked and released to the scene .Mulberry Bayswater Outlet. He actually came back and was helping us at the end of the fire roll things up, " Captain Wallert added. "In this photo right here, this was toward the end, it was a hundred degrees on the outside, and about a hundred degrees on the inside as well, " Wallert stated. Firefighters had cleared the scene by around noon. The cause of the fire is still under investigation. An ambulance was seen leaving the plant running with lights and siren, but it was responding to another call. The Red Springs Firefighter was treated for heat exhaustion. No other injuries were reported. The cause of the fire remains under investigation.