A national representative for Unifor, the union that represents workers at the shipyard, said they believe the man committed suicide and were linking it to disciplinary action taken against him.
But Rick Rose said the union doesn't know whether there was a link between the suspension and the man's death.
"I couldn't possibly be certain there's any correlation whatsoever, but you can imagine there's probably some folks linking those two circumstances," he said.
RCMP Staff Sgt. Gerald Grobmeier said the man's death is under investigation but "it appears to be from a self-inflicted gunshot wound."
Rose said the walkout was also triggered by growing frustrations over growing numbers of disciplinary letters, firings and suspensions of other employees.
"When the workers learned of the tragedy of one of their colleagues ... they took a spontaneous, emotional reaction to rise up and express their frustration," said Rose.
The Irving Shipyard identified the man as Peter MacKenzie.
"Our thoughts and hearts go out to Peter's family and friends, and to all here at the shipyard who worked with him," the company said in a statement.
"It is not appropriate to speak about details regarding individual employees — our objective here is to respect family and friends and the employee's memory."
MacKenzie's family could not be reached for comment.
At the entrance to the shipyard, workers gathered through the morning, crossing the street and encouraging passersby to honk their horns.
Bob Couture, a co-worker who knew MacKenzie, said the man was suspended because of alleged safety concerns over the way he set up scaffolding. But Couture said MacKenzie also faced other stresses in his life.
"When I came in this morning, I was really upset. And the boys are just not putting up with it," Couture said.
"A lot of people here are blaming the situation he's been under, the stress he's been under. ... We see it as bullying."
Rose said the details of why the man was disciplined are still being discussed with management.
"The challenge for us on this specific incident is that it just happened this week and subsequent to any kind of event like that, an investigation ensues," he said. "And that hasn't happened yet."
Shop steward Ryan LaPointe, an electrician, said part of the anger stems from a series of firings at the yard over the past year.
"A bunch of people have been fired for no reasons," LaPointe said. "We've had enough."
Deborah Page, a spokeswoman for Irving Shipbuilding, said in an email the company has "established processes in place to deal with issues raised. These are agreed to by both union and management. We respect these processes."
Workers at the shipyard voted last November in favour of a new six-year collective agreement with Irving Shipbuilding.
The company said the deal covered 1,000 unionized workers at the yard.
At the time, Irving also announced president Steve Durrell had left the company, after working there for 27 years.
The Irving Shipyard was selected in 2011 to build Canada's new fleet of Arctic patrol vessels and warships. It is still negotiating contracts for the construction of the ships.