(CNN) -- Jim Serowski said his employees told him they planned to skip work on Thursday to participate in "A Day Without Immigrants," the nationwide day of protest.
Serowski, founder of JVS Masonry in Commerce City, Colorado, said his message to them was clear and unwavering:
"If you're going to stand up for what you believe in you have to be willing to pay the price."
As promised, when his foreman and some 30 brick layers failed to show up for work he fired them all with no regrets, he said.
RELATED: 18 fired for joining in 'Day Without Immigrants'
He insisted it had nothing to do with politics and everything to do with business.
"I stand by what I believe in. I didn't do anything wrong," he said in a phone interview Sunday.
"They were warned, 'if you do this you're hurting the company, and if you go against the team you're not a member of the team.'"
As US President Donald Trump continues his tough stances on immigration, people skipped work on Thursday and businesses closed to show how much immigrants contribute to the nation's economy.
Others, including Serowski, responded with pink slips to employees who took the day off.
His foreman told CNN affiliate KDVR that it was important for him and his workers to join the protest. Some of his masonry workers have relatives who are afraid to leave their homes out of fear they may get arrested or deported, he said.
But Serowski said it was a slap in the face to people like him who have long supported immigrant labor. He's known many of his employees for nearly two decades, ensuring they were paid when he did not have work for them.
"I've gone above and beyond for these people," he said, seemingly distraught. "No one is going to dictate how my company is run."
Bill McNally, owner of "I Don't Care Bar and Grill" in Catoosa, Oklahoma, said his 12 line cooks gave him no heads up that they planned to participate in the day of action. They didn't even call to say they were not coming in.
Consequently, he said they were fired just like anyone else who's a no-show for work.
"I'm on their side but we have rules at "I Don't Care Bar and Grill." If you're going to be late call in. If you're not coming to work call us. That's the American way," he said.
Six of the fired Hispanic immigrant workers told CNN affiliate KTUL they felt they had been unfairly terminated. They wanted to stand in solidarity with other immigrants but they did not think it would cost them their jobs, a translator for the group told KTUL.
Under US labor law, workers can be fired with no warning and no reason given.
McNally also insisted it had nothing to do with politics. Had he known about the protests he said he would have closed the restaurant in solidarity.
Why fire them, then?
"They just forgot about the 50 other people who work here," he said. "If the cooks don't show up then servers don't have jobs and customers can't eat."