Last Saturday afternoon, a man in a Tampa Bay Lightning shirt and khaki shorts waited in line at a Tampa Walmart. Beside him was a little boy wearing a T-shirt emblazoned with the superheroes Captain America, Iron Man and the Hulk.

The man was white. The boy, 9, was black. He held the man's hand as they waited to pay for their snack.

And that was enough to raise the suspicions of a woman, who was also black, in the Walmart that day.

She was concerned enough that she asked to take a picture of the boy, saying he looked like her grandson. As the pair left, she got the man's license plate number and a description of his car.

She called 911 and described them down to the three superheroes and the color of the Hyundai.

According to the dispatcher's notes, the woman said she thought it "suspicious" that a white man was holding hands with a black child. She said the man seemed in a hurry to get in the shortest check-out line. She said the boy kept looking around.

She said she thought the child was being kidnapped.

You might have recognized the man in line that day — Frank Robertson, longtime local TV anchorman until he retired in 2009, married to also-well-known former anchor Kathy Fountain. The child with him that day was his "little" — which is what they call kids in the Big Brothers Big Sisters program that pairs adult volunteers with children who need them.

And this is the world we live in.

The police called Robertson. The officer wouldn't say what it was about but wanted to question him in person.

Robertson, 67, handed over his driver's license. He explained about being the boy's "big." That day, they had gotten a Happy Meal at McDonald's and played video games in Ybor City — the boy had never been — before they hit a Walmart on E Hillsborough Avenue and Robertson took him back to his grandmother's house.

Police drove to the grandmother's. She confirmed the story. Robertson has been a part of the boy's life for more than a year.

He told me this week he didn't want to make too much of it, but the experience unnerved him. He had posted a short description on Facebook about being "given a vivid and personal reminder of how serious the racial divide is in our country right now." He wrote about how the boy instinctively holds his hand when they're out in public together. He thought the woman "could have simply asked me about our relationship" but called police instead. (Police do not release the names of people who call 911.)

He said it saddened him.

His post provoked hundreds of comments on Facebook, many lauding him for volunteering, some lamenting the state of the world, a couple talking about their own encounters.

What has happened to people?

The woman probably had the child's best interest at heart, but she could have handled it differently/better

Hoping there will come a time again where we aren't the Divided States of America any longer.

It is worth noting that an Amber Alert was issued for a much younger black child in Largo that same weekend. And that these days, we're told if you see something, say something. The younger boy's body was later found in the woods; his mother, charged with murder. That too is the world we live in.

Race-based assumptions are everywhere, though often the other way around: a white Yale student calling police because a black woman, also a student, was napping in their dorm's common room. Two black men infamously arrested while waiting for a business meeting at a Philadelphia Starbucks. A young black man on his way home from church with his white grandmother who was handcuffed by Wisconsin police because two passers-by thought he was robbing her.

Robertson says the boy sometimes asks him when they're out why people are looking at him.

"Maybe because you're with an old guy who happens to be white," Robertson tells him.

What happened at the Walmart that day was "just disappointing is all," he said this week. "It's not going to change my approach to being his big. … He needs me, and I need him."

I called Pam Iorio, the former Tampa mayor who is now president and CEO of Big Brothers Big Sisters of America. She listened, then pointed out how the program puts together two people from very different backgrounds and often different races, and how they form real relationships that cross barriers anyway. And that someone thinking something was wrong that day speaks to why we need this.

"More work to be done," she said. And maybe we can agree at least on that.