On Dec. 2,1943, German bombers attacked American ships in the harbor at Bari, Italy. As summarized on an Internet site maintained by professor John H. Lienhard of the University of Houston, the bombers sank 16 ships, partially destroyed four others and set off two major explosions. Fires burned while rescuers pulled hundreds of sailors from the harbor.

"At first, many of the survivors seemed to be all right, though a few mentioned the odd smell of garlic," Lienhard wrote.

"Soon they began showing symptoms — stinging eyes, skin lesions, a variety of internal problems. Four survivors died later the first day, nine the next. By the end of a month 83 men, out of the 617 who'd made it to the hospital, had died."

One of the ships had carried 100 tons of mustard gas, which the Army later said was carried as a deterrent, according to Lienhard.

The United States built up an enormous stockpile of nerve and blister agent in the years after World War I. These deadly weapons were collected at nine Army bases including Tooele Army Depot in Utah's western desert.

About 44 percent of these deadly chemical weapons were collected at Tooele Army Depot. The arms storage area later was renamed Deseret Chemical Depot.

By the middle 1990s, munitions and chemical agent stored at Deseret Chemical Depot amounted to 13,616 tons of VX and GB nerve agent, mustard and Lewisite (made by mixing mustard agent with arsenic).

All are deadly. VX is so toxic that a minute drop of it on the skin can kill.

The chemicals were in steel containers holding about one ton of GB, and in battlefield weapons — spray tanks to be mounted on airplanes; projectiles; cartridges; land mines; rockets. Of 30,000 rockets at the Tooele base, at least 1,000 leaked. When leakers are discovered, to contain the vapors they are placed in special devices called "overpacks."

In 1985, Congress passed Public Law 99-145, which requires the destruction of all chemical arms. In 1993, this country signed the Chemical Weapons Convention; the Senate ratified the treaty in 1997. This international treaty commits signatory countries to the safe destruction of their chemical arms by 2007.

The Army decided the safest method was to destroy the material where it was stored, rather than move it to some central location and get rid of it there.

A prototype incinerator was built at Johnston Atoll. It began to burn chemical arms in 1990.

The Johnston Atoll Chemical Agent Disposal System ended its task on Nov. 29. It had safely destroyed 412,732 rockets, projectiles, bombs, mortars, ton containers and land mines containing chemical agent, according to the plant's project manager, Gary McCloskey.