They arrived at the store and disabled all of the automatic lights in the building, in an attempt to avoid undo attention.
So they sat. And waited. And waited. And waited some more.
They heard chants of protesters as they marched nearby. They saw bottles being hurled at police, and they saw police fire rubber bullets back at protesters.
A few blocks away, a building was partially destroyed, its windows broken and its contents askew.
Four hours later, the crowd dispersed. Mr. Vuko and his employee went home. The business was safe.
At least for now.
"It's crazy," Mr. Vuko said. "I wasn't trying to a hero. I just couldn't sit home knowing they might break in.
"We were just trying to scare whoever might try to come in away."
Business at the store, one of four Walker Point S/Quick Nick locations, was down considerably over the last couple of months, hit hard by the COVID-19 pandemic. Workers with offices downtown, like other downtowns across the nation, were now working remotely, with little need for tires or automotive service.
Now the location could suffer collateral damage as a result of nationwide protests and looting in the aftermath of the horrifying death of George Floyd, an African-American man who died by being forcibly restrained by a white police office in Minneapolis and videotaped for the world to watch.
Mr. Vuko wants to be clear: He supports the peaceful protests.
"I am just as outraged about the murder of George Floyd, and that cop needs to be charged with second-degree murder," he said. "If they riot, that's a different story."
In the wake of the incident, Mr. Vuko said he has come to realize two things.
First, he has insurance on his buildings. Saving his building is not worth the risk, he said, with a wife and four children at home.
Secondly, he said, he needs to purchase a firearm for self-defense.
"I've been talking about it for a while — to get (a firearm) for self defense — in case I need it. I want to make sure I take all of the necessary courses first. I've never gotten one, because I worry about the kids."
Mr. Vuko is a respected member of the Nebraska business community, according to the many comments left on the Walker Point S Facebook page.
"You treat your employees like family," one man wrote, "and if something happened, you would still have the burden of taking care of those families even if you had to rebuild."
In a video message posted on the site a couple of months ago, Mr. Vuko told customers he was offering 25% off service and free pickup and delivery to and from local hospitals for health- care workers.
For now, Nick Vuko's business is safe.
Let's hope and pray, for him, his family and the Nebraska community, it stays that way.