Two firefighters were killed and a third wounded Sunday when they were shot as they responded to a wildfire on an Idaho mountain that was set to lure them into an ambush, authorities said.

A tactical response team used cell phone data to zero in on a wooded area where they found the body of what's believed to be the lone suspect and a rifle nearby as flames were rapidly approaching, Kootenai County Sheriff Robert Norris told a news conference late Sunday night. Norris explained that a signal was detected coming from a cell phone that was in the same spot since about 3:16 p.m. local time and authorities honed in on it.

The body and firearm were quickly removed from the scene because the fire was rapidly approaching, he said. Gunfire had been exchanged with the suspect and it was unclear whether he'd shot himself. At one point, authorities had two helicopters overhead with snipers in them.

A shelter-in-place order for area residents was lifted but residents were urged to stay alert because the fire was still burning.

Norris said, "We do believe that the suspect started the fire, and we do believe that it was an ambush and it was intentional. These firefighters did not have a chance."

The suspect's name wasn't released and Norris didn't say what type of rifle was found or what investigators think the gunman's motive might have been.

He said the blaze covered about 20 acres and there were 300 law enforcement officers at the scene including some from Spokane, Washington and the FBI.

Sheriff's officials said crews responded to a blaze on Canfield Mountain just north of Coeur d'Alene around 1:30 p.m. and gunshots were reported about a half hour later. The gunfire continued over several hours.

Three victims were brought to Kootenai Health, said hospital spokesperson Kim Anderson. Two were dead on arrival.

The wounded firefighter was "fighting for his life" after surgery but was in stable condition, Norris said.

One of the slain firefighters was from the Coeur d'Alene department and the other was from Kootenai County Fire and Rescue, Norris said, adding that the wounded firefighter is with the the Coeur d'Alene department.

Gov. Brad Little said "multiple" firefighting personnel were attacked. "This is a heinous direct assault on our brave firefighters," Little said on X. "I ask all Idahoans to pray for them and their families as we wait to learn more."

Norris told reporters as the situation was unfolding that, "We still have civilians that are coming off of that mountain. We might have civilians that are stuck or in shock on that mountain, so this is a very, very fresh situation. We are prepared to neutralize this suspect who is currently actively shooting at public safety personnel. We are prepared to neutralize this suspect as quickly as possible."

He said at the late night news conference that authorities think all civilians are off the mountain, including any hikers who were in the vicinity.

Coeur d'Alene is close to the Idaho-Washington border, about 30 miles from Spokane.

Pat Milton contributed to this report.