SUMMERVILLE -- Tina Williamson vividly remembers the day her son was killed in an industrial accident on the North Charleston waterfront. She remembers being shrouded by the overwhelming shock. But most of all, she remembers the lingering numbness.

"I felt like my son had been murdered because of the way he had been taken from me," she said of 18-year-old Matthew Williamson.

Six years later, Williamson is trying to rekindle the idea of a memorial to her son -- and to everyone else who died while on the job in South Carolina.

Thursday is national Workers Memorial Day, a 20-year-old recognition that has gained little traction in the state. Williamson wants that to change. "It's not a political thing, it's not whose side you're on. These workers need to be honored," she said.

Williamson, 45, doesn't call herself an activist. Instead, she refers to herself as a mother who doesn't want anyone else to suffer the same pain she did, of losing a son or daughter in a place where they are supposed to be safe.

It was around 5:30 in the afternoon Dec. 1, 2005. Williamson had driven to Detyens Shipyard to pick up Matthew, a 2005 graduate of Summerville High School. He had followed in his father's trade, working part-time as a maritime pipefitter ahead of going to college.

When she approached the gate, she was met by a whirling blur of flashing emergency lights.

Matthew Williamson had been in a holding tank area of a military supply ship being refitted in dry dock. There was an accidental release of waste.

Other men escaped. Williamson did not. An autopsy and medical tests showed he was overcome by hydrogen sulfide, a colorless but toxic gas produced by raw sewage.

After her grief subsided, Williamson tried to regroup. She learned about the workers' memorial day and wanted to start a gathering here, to be a meeting site where victims' families could draw on their collective strength. She scoured obituaries and news stories for names of those lost, making contact with their next of kin. Her first couple of events drew a scattering of interest. But she wants more.

For this year, Williamson is sponsoring a candlelight service at Palmetto Land Baptist Church in Summerville at 6 p.m. Thursday. First District Republican U.S. Rep. Tim Scott is the guest speaker. The recognition is for anyone who died on the job, in incidents ranging from motor vehicle and equipment accidents to acts of violence. In 2009, 73 people died during their work shifts in South Carolina, the latest available tabulations show.

"We honor and remember all South Carolina workers, not just the Lowcountry fallen workers," she said.

Labor issues traditionally draw few outspoken voices in South Carolina, a right-to-work state where union interests are habitually drowned out by the prevailing political winds in the Statehouse. Donna Dewitt, president the AFL-CIO in South Carolina, said lawmakers are so outwardly sensitive to business needs that many appear overzealous in stamping out any form of pro-labor sentiment.

What's lost in that argument, she said, is that worker and employee issues are multifaceted, not simply cases of wage and dollars.

"We have people calling us all the time about dignity in the workplace, and about safety," she said. "It's just not wages first." Unions represent about 70,000 workers in South Carolina.

Even with those numbers, the workers' memorial day has little following. One of the more visible Charleston-area labor unions, the International Longshoremen's Association, has nothing scheduled for Thursday, Ken Riley, president of ILA Local 1422, said last week. But he said he supports what Williamson is trying to accomplish. "Someone who goes through that can be the catalyst that ignites that type of recognition," he said.

Williamson said her effort is not about injecting worker rights into the debate. She just wants those still grieving, or those looking to recognize the loss or sacrifice of a co-worker, to know they have an outlet.

Reach Schuyler Kropf at 937-5551.