Arson may be the cause of a wind-whipped blaze that injured four firefighters Monday afternoon on Salt Lake's north side.

The four were ascending interior stairs when a wall of fire blew them down the stairs of the wood-frame and brick residence at 720 N. Third West, said Battalion Chief Gordon Nicholl. They were looking for people who reportedly were in the house."There was probably a back draft on the second level, and it blew the two crews of firefighters down the stairway," Nicholl said. "They had to go through that wall of fire and down the stairs to get out of the house."

The home's renter, Freida Abbott, was blocked by a police car rerouting traffic at Sixth North on her way home. "Nobody was in it (the home). But everything I own is in it," said Abbott.

Damage is estimated at $25,000, and firefighters say the home is probably a total loss.

An investigation has revealed the fire started in the rear of the house, possibly in a window well. The fire got on the inside of the siding and climbed to the roof where the wind fanned the flames.

"The cause is definitely suspicious," Nicholl said.

Nicholl said the fire department has responded to three arson-caused fires in the neighborhood of Seventh North and Third West in the past three months.

Five firefighters have been injured in the last three days, including one who suffered smoke inhalation battling a Friday fire that killed two children.

In Monday's blaze, Lt. Gene Minor suffered smoke inhalation and a severely bruised shoulder. Paramedics Merrill Bone and Mike Snodgrass suffered burns over their faces, ears and necks along with smoke inhalation.

Engineer Mike Reese suffered burns on his ears and smoke inhalation. All were treated and released at Holy Cross Hospital.

"Their turnout gear protected them from the flames, but around the neck and ears they suffered super-heated air burns," Nicholl said.

Winds to 30 mph helped fan the flames in the tinder-dry residence, which the battalion chief said had much to burn. "It moved from the basement all the way up to the top level," which had been remodeled from an attic storage area to a living area.