WELDON SPRING — They were honored with a wreath laying, a gun salute and the playing of taps.

Those who were feted Friday evening weren't being heralded for their military service. They were former nuclear plant workers, and the ceremony conveyed the idea that their efforts may have been just as important.

"They built and maintained our nuclear weapons," said Denise Brock, an advocate for nuclear workers at three St. Louis-area Mallinckrodt plants. "Without them, we wouldn't have made it through World War II. We wouldn't have made it through the Cold War. But their services and sacrifices were buried. Now, it's all out in the open."

The ceremony, at the Weldon Spring Interpretive Center on a site where explosives and Cold War bomb materials were made, was part of the first National Day of Remembrance for All Nuclear Weapons Workers.

An estimated 3,500 people worked in the dangerous early days of the atom bomb program in the St. Louis area. Decades later, many have died of cancer that is believed to be radiation-related.

The ceremony was organized by Brock, an advocate for workers who developed disabling or fatal illness because of toxic substances and hazards used in the production and testing of nuclear weapons. She has been described as the Erin Brockovich for area nuclear workers, a comparison to the legal crusader made famous by Hollywood. Her father worked at a plant from 1945 to 1960 and was later diagnosed with lung cancer and leukemia that the federal government linked to radiation exposure at the plant.

Nuclear workers included employees of Mallinckrodt Chemical Co. plants in St. Louis, Weldon Spring and Hematite.

The Weldon Spring site features a seven-story-high tomb of radioactive waste. The mound contains radioactive waste and chemicals, covers 45 acres and stores 1.5 million cubic yards of material. An interpretive center was opened at the site in 2002.

Like soldiers on the battlefield, the workers faced danger and death, though many didn't know it.

Howard Shumate of Spanish Lake had no idea of the risk he took when he handled uranium for 32 years and used only gloves to protect himself, he said.

"Nobody ever told us anything about the harm," said Shumate, 87. "They didn't tell us much of anything. I never thought about it."

He was not sickened by the exposure but said he knows several people who were not as lucky. He also said it was good to be recognized for the work that he and his co-workers did so many years ago.

"I think it's great. It's something we should be proud of," he said.

During the service Friday, many in the crowd of a few hundred held American flags. Representatives of various agencies, including the Missouri Department of Natural Resources and the federal Energy Department, praised the former workers' contributions. Dozens of the honorees stood to be recognized.

That recognition had been a long time coming for people like 83-year-old Tony Windisch of South County. He worked with uranium for 22 years at Mallinckrodt plants, starting when he was just 19.

For years, he couldn't talk about his work, he said.

"Everything was a big dark secret," he said. "We couldn't even tell our families what we were doing."

Windisch has prostate cancer and is working to prove to the government that the cancer was caused by radiation exposure so that he can seek compensation, a process that he's not alone in trying to achieve, but a fight he's not going to quit.

Said Brock: "We owe these guys a lot."