Investigators believe a welding torch may have ignited tires, potentially toxic trash and abandoned mobile homes in an illegal west-side trash yard.

The fire that began at 2:45 p.m. Monday in a vacant yard at 56th West and North Temple had two dozen firefighters, several engines, water trucks and fire investigators hopping."What we got here is a dump," said Salt Lake Fire Battalion Chief Jim Kleine, reviewing some of the strange contents, including, tires, timber, beds and a host of other flammable items.

The site is the future home of the city's sewer treatment plant, officials said.

Flames were jumping 20 feet into the air from metal drums that Kleine said contained "toxic something" as crews contended with the difficult access and lack of water to extinguish the fire.

Mobile homes that outgrew their usefulness, farm machinery, metal beds, a livestock trailer and hundreds of tires several feet deep were charred and smoldering as winds in excess of 20 mph fanned the flames over the barren landscape.

Kleine was hesitant to use city equipment to dig under the fire, using an earth mover instead to shift dirt onto the blaze.

Livestock and horses were escorted to higher ground by Salt Lake County Animal Control employees as investigators prowled the grounds.

"It's all wide open," said Steve Herrmann, a city fire investigator. "More often than not, they (illegal dumpers) don't have to go to the dump; more than likely the stuff they're dumping is illegal. And using a torch on a day like this is just plain stupid."

City investigators said whoever started the blaze that burned nearly five acres off I-80 could be fined at least $299 and given a six-month jail sentence.

The owner of the property was unknown, officials said. "You come to a situation like this and you don't know for the life of you what's here," said Kleine, adding the dumping must have gone on for at least a decade.

A state Air Quality Bureau investigator was at the scene to monitor potential health hazards posed by the flaming debris and tires.

Crews spent four hours surrounding the flames at the tire fire, and Kleine said it likely would smolder for several days.

While Salt Lake City crews were contending with the tire fire, Salt Lake County firefighters extinguished a small grass fire at 35th South and 15th West that erupted about the same time.