Sacramento firefighters battled a fire Wednesday that sent a plume of black smoke high into the sky north of downtown and sent three firefighters to the hospital for smoke inhalation.

The blaze started about 1 p.m. at River City Waste Recyclers in the 700 block of North B St.

Assistant Fire Chief Niko King of the Sacramento Fire Department said firefighters were expected to continue monitoring the site today.

The fire, the cause of which is under investigation, began among 300 car tires and construction site waste before moving to recyclable materials on the company's lot, King said.

The recyclable materials had not yet been been compressed for processing, allowing the fire to spread rapidly, King said.

"All we know is the owner came in at 1 o'clock and saw the smoke, and we called 911," said Cheri Borba, manager of the Scott Naake Paper Co., a neighbor of River City Waste Recyclers.

"We couldn't see through the thick smoke," said Borba, who described it as smelling like burning wood, tires and chemicals.

The smoke cloud, seen even in south Sacramento, started out black, changed to white and eventually faded into an opaque beige. For a while it obscured visibility within 100 yards of the site.

King confirmed that firefighters had trouble getting to the seat of the fire because of the heavy smoke. They finally made headway when crews brought in a tractor to break up the fuel and soak the base of the fire.

Five firefighters suffered from smoke inhalation, King said. Three were taken to a nearby hospital, while two were treated on-site after being tested for high carbon monoxide exposure.

"We usually go right up to the fire line, and once you put on your breathing apparatus, the clock starts ticking," King said. "You have 20 minutes or so to work. When you take it off, you are still in the proximity of all of the combustion. For us, it's a pretty high dose over a small period of time."

King said a health advisory was issued to alert people in the immediate area with pre-existing respiratory conditions to leave the area.

The Fire Department set up air-monitoring equipment to track the smoke's effect in residential areas and created an overnight crew rotation to keep tackling the fire and minimizing the smoke.

Police routed traffic off Richards Boulevard between Interstate 5 and Highway 160 and asked workers in the area to move indoors as efforts to extinguish the blaze continued. Traffic should be back to normal this morning, King said.

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