After 18 employees at a Tennessee-based painting company skipped work this week to attend a pro-immigration rally, they received a brutal lesson about right-to-work laws they won't soon forget.

According to KTNV-TV, 18 employees at Nashville's Bradley Coatings were fired after they informed their supervisors on Wednesday they were missing work the next day to attend the nationwide protest, "A Day Without Immigrants."

The protest sought to show the significance that immigrants play in the U.S. workforce while protesting President Donald Trump's immigration policies.

However, on Thursday when the employees didn't show up to work, they learned that they had been terminated.

"We are the team leaders directly under the supervisors and they informed us last night that we could not go back to work and the boss said we were fired," one anonymous employee told KTNV.

He added, "I would tell [my boss] he was unfair, after working for them for so many years, giving him our best. They could not understand that it was just one day. We were going to make up that day on a Sunday, but they didn't understand that, and it was not the best way. They didn't give us an opportunity and just told us we were fired."

Still, the company was within their rights to terminate the employees for not showing up to work, according to Tennessee Department of Labor and Workforce Development spokesman Chris Cannon.

"Tennessee is an employment-at-will state which basically means an employer can end your employment at any time without reason or cause. Of course there are a lot of different stipulations, civil rights issues that could stop them from doing that," he told KTNV.

The company's lawyer later released a statement to clarify that the employees were not fired because they attended the rally, but because they skipped out on work that included sensitive projects that clients contracted Bradley Coatings for.

According to KTNV, seven other Bradley Coatings employees quit after they learned their colleagues had been terminated over their absences.

They weren't the only employees to understand the harsh realities of skipping work in a right-to-work state. Twenty-one people were fired in Lexington, S.C., after they too skipped on work to attend the protest, according to WLTX-TV.

Watch the full story below: