May 26, 2000 - A risky fire suppression tactic-not the ignition of the prescribed burn-sparked the crown fire that swept through Los Alamos and grew into the largest wildfire in New Mexico's history, federal investigators told Forest Magazine.

John Robertson, Dan O'Brien and Joe Stutler, all fire experts with the U.S. Forest Service, said that the prescribed fire set by the National Park Service would have died out on its own had it been left to burn. Instead, they said, it was a backfire set by firefighters that erupted into an out-of-control forest fire.

The trio said the backfire was set in an area where the chance of flames escaping into a tinder-dry, thickly wooded canyon was high. Stutler said that fire managers directed crews in the field to bring fire down slowly into that area from a moister and higher elevation, in accordance with the original prescribed burn plan. In addition, the crews were to use mechanical means to remove flammable deadwood and brush from the area, near New Mexico State Road 4 a few miles southwest of Los Alamos. But due to a lack of personnel, the fateful decision was made at the scene to immediately burn the area instead.

Robertson, who confirmed this scenario, said he believes firefighters, in an urgent bid to create a firebreak, "were trying to beat the winds." Instead, high winds hit the tinder-dry area precisely when it was being ignited, the investigators said.

According to Stutler, the decision to set the backfire was made by Park Service personnel who were managing the firefighting efforts on the ground at the time.

Stutler, Robertson and O'Brien participated in the federal government's investigation of the Cerro Grande fire.

The blaze forced 25,000 people to flee, scorched 47,000 acres, left 405 families homeless and damaged Los Alamos National Laboratory, the storied nuclear weapons research facility.

The investigators' findings are clearly detailed in a little-noticed appendix of the exhaustive government report on the Cerro Grande fire issued last week by Interior Secretary Bruce Babbitt. But their basic conclusion about the immediate cause of the fire is clearly stated in the main body of the report: "Once the prescribed fire was declared a wildfire, additional fire (was) introduced that ultimately produced the source of spotting and escape when high winds developed."

The investigators' findings do not change the fact that the National Park Service, by igniting the fire, set in motion the chain of events that led to the disaster. At a press conference in Santa Fe last week, Babbitt said that the Park Service was taking full responsibility for the blaze.

But the investigators' determination that the deliberate setting of a backfire caused the inferno is at odds with the basic conclusion of the larger report and with the overriding message that has been given to the public: that the Cerro Grande fire was essentially a prescribed fire run amok.

Firefighters have lost control of backfires before-and those backfires have burned private property. A backfire set by firefighters battling the series of blazes that hit Yellowstone National Park in 1988 nearly burned down the Montana town of Cooke City.

In New Mexico, "it wasn't the planned prescribed fire, but the unplanned reactive emergency fire suppression backfire that blew out the project area," said Tim Ingalsbee of the Western Fire Ecology Center in Eugene, Ore. In the wake of the Cerro Grande fire, serious questions have been raised about whether prescribed burning should be used in the future. Wallace Covington, a fire expert from Northern Arizona University in Flagstaff, has gone so far as to suggest that the forests of the West have become so overgrown that setting prescribed burns is too risky. The best alternative to reduce the fire hazard, Covington says, is to mechanically remove trees-in other words, to log.

While the Cerro Grande fire was still raging earlier this month, Babbitt imposed a thirty-day moratorium on prescribed fires that is still in effect. Itis widely anticipated that the moratorium will stay in place longer.

If prescribed burning is banned, its advocates say, or if its use is seriously restricted, fire management officials would be deprived of a critical tool in the on-going effort to reduce the widespread catastrophic fire hazard in the West-a hazard directly due to almost a century of fire suppression.

Robertson's, O'Brien's and Stutler's investigation, however, raises the question of whether the storm of controversy and criticism aimed at prescribed burning in the wake of the Cerro Grande fire is justified. Robertson, O'Brien and Stutler, in separate interviews this week with Forest Magazine, made the following points:

• If it had been left to burn of its own accord, the prescribed burn would have eventually burned out.

The trio bases this conclusion on the fact that the prescribed burn was set in a high-elevation (close to 10,000 feet) area that was relatively moist. It was so moist, Robertson said, that Bandelier prescribed burn personnel were having difficulty coaxing the fire to burn hot enough to clear the area of underbrush-one of the main goals of setting the fire in the first place.

"If they had kept it as a prescribed burn, it wouldn't have gotten out of control," Robertson said. That would have been true, Robertson added, even if extra people and equipment had never been requested.

• The decision to declare the prescribed burn an out-of-control wildfire led to the more aggressive tactics that caused the burn to get away from the firefighters.

"Everything became more accelerated and more urgent when it became a suppression effort," Robertson said.

The decision to switch to a fire-fighting mode was made in part because prior to the crown fire of Sunday, May 7, a few small spotfires did occur outside the prescribed burn area. However, according to Robertson, those were mostly minor and were, in fact, contained-including the largest one, which was about 20 to 30 acres in size.

But possibly because of the proximity of the prescribed burn to Los Alamos, there was concern. When Bandelier personnel contacted the Santa Fe National Forest for backup in the form of extra people and equipment, Robertson said there was confusion about whether funding for such assistance could be made available if the fire was still being treated as a prescribed burn.

To get that aid, Robertson said, it was decided the fire had to be declared an out-of-control wildfire-in other words, a fire that needed to be extinguished with all means available, rather than a prescribed fire that needed to be guided and monitored to ensure that it behaved as intended. Once that step was taken, various options for attacking the fire were considered. Eventually, according to Stutler, it was decided to bring fire downhill slowly toward State Road 4 to create a firebreak while at the same time clearing out brush and deadwood near the road. But because of a lack of manpower that strategy was changed and firefighters instead started burning along both sides of State Road 4, Stutler said.

That was risky for two reasons: it put fire, which burns uphill more readily, at the bottom of a steep area; and it put fire near a thickly forested canyon. It was from this area-where the ultimately disastrous backfire was lit-that flames were carried by high winds across the road and into the canyon, called Frijoles.

"It was the suppression action that put fire along Road 4 that resulted in the escape from the project area," Robertson wrote in his report.

-- Keith Easthouse is associate editor of Forest Magazine.