With all the rockets gone there is a 91 percent risk reduction to the public, depot spokesman Bruce Henrickson told the East Oregonian newspaper of Pendleton.

The rockets are being burned in a high-temperature oven built especially to get rid of the chemical weapons at the depot, which housed about 12 percent of the national stockpile when the incineration program started in August 2004.

Henrickson said there is an atmosphere of "professional restrained excitement" at the depot. "We're not done until we're done, but it's a historic milestone for the depot and the community," Henrickson said.

He said the destruction of the remaining rockets could be postponed if anything went wrong, such as gate repairs on the processing line that stopped the burning of the rockets and warheads for several hours on Friday.

Henrickson said the destruction of the remaining chemical weapons won't be completed for years.

He said the rockets carry a "triple whammy" because they are self-propelled, contain nerve agent and contain explosives.

By contrast a bomb has two out of the three since isn't self-propelled.

The rockets are about 6 feet long and can travel 6 miles. Each contains 9-10 pounds of GB nerve agent and was designed to be fired from a shoulder mounted rocket launcher.

Unexpected fires in parts of the incinerator have stopped destruction briefly at times but Henrickson says there have been no major accidents.

The United States is under treaty obligations to destroy the 7.4 million pounds of chemical agent in bombs, artillery shells, rockets and other weapons at the depot by 2012.

Cost of the project has been estimated at $2.4 billion.

(Copyright 2006 by The Associated Press. All Rights Reserved.) UPDATE: What to do with Umatilla weapons depot land? A Land Reuse Authority mulls over the options.