UPDATE: Thick smoke and heavy flames could be seen for miles.

Cell phone video sent to Channel 3 shows a funnel of black smoke high in the sky. While some watched from a distance, others saw it up close.

"Windows were orange, and flames coming from the top of the building and I called 911. She asked me if it was fire and smoke and definitely a fire because I could see flames from the top of the building," said Titan Long, works next door.

The fire broke out just after 6:00 a.m. Tuesday. Several people reported seeing smoke from miles away, including firefighters arriving at the scene.

"They could see the magnitude of the fire and so they called in for a second alarm response, that brought in roughly 12 fire companies," said Bruce Garner, Chattanooga Fire Department.

Firefighters attacked the blaze from the ground and from above, pouring thousands of gallons onto the building.

The battalion chief knew the structure was a total loss, so they focused their efforts on saving the Cabex woodworking shop next door.

"Firefighters decided to strike a line there and keep the fire from spreading to the other business and they succeeded in doing that," Garner said.

A track hoe was brought in to knock down potentially hazardous walls and move debris so firefighters could put out hot spots.

Investigators say the building has been vacant for years, and are not sure what caused the fire to burn so fast.

Eyewitnesses say it's unlike anything they've seen before.

"It would have to be flames probably three or four times of the building over there," Long explained.

Investigators still don't know what caused the fire, they will work to learn those details in the coming days.

Workman road is still closed at this time.

No one was injured in the blaze, and the cause is being investigated.

Stay with the WRCB app for updates to this story.

PREVIOUS STORY: The Chattanooga Fire is on the scene of a fire at a recycling business on Workman Road.  

The call came in just after 6:00am Tuesday morning.

We have a crew on the scene and will bring you updates as they become available.