O regon environmental regulators are justifiably concerned about the rough start of the Army's sprawling new weapons incinerator at the Umatilla Chemical Depot near Hermiston.

The state's Department of Environmental Quality suspended operations at the facility recently after the third in a string of fires involving aging Cold-War-era rockets that were being cut apart before incineration. The fires, so far unexplained, came on the heels of several safety-related employee mistakes, which led to a performance audit that came out highly critical of the operation's management and training.

A rocky beginning, indeed.

Thus, it's reassuring that the state's DEQ watchdog agency called a timeout while the Army and the incinerator's operational contractor, Washington Group International, figure things out.

Evidently, they've already figured out a few things about the management and training issues. After the contractor conducted its internal audit in February, an operational overhaul led to markedly improved safety and efficiency at the plant. Then, just when the weapon-destruction program looked most promising, the first of the three rocket fires broke out on April 7.

Though the problem is serious, it's not quite the catastrophe that sensational broadcast news reports may have led some to believe. Keep in mind:

The three rockets burst into flames as a robotic machine chopped into their propellant sections. The explosives and sarin nerve agent had already been removed, and there was no release of chemicals into the environment.

No people were harmed, and damage to equipment was minimal. The heavily fortified room, with 28-inch-thick concrete walls, was designed to withstand such fires, or worse.

Before the trio of fires, more than 14,500 such rockets had been successfully destroyed at the Umatilla depot. The work is being done with proven technology that successfully eliminated a much larger stockpile of deadly weapons on Johnston Atoll in the Pacific.

"Fires are never a small deal for us," Mark Evans, Washington Group's president, said in Portland this week. He vowed a "relentless focus on safety" and promised that the company will never rush the weapons destruction to meet production objectives.

Oregon regulators should hold the contractor to those standards. And all residents of Oregon and Washington should remember, as more such setbacks inevitably occur at the Umatilla incinerator, that continued storage of these leaking, unstable old chemical weapons is far more dangerous than destroying them.