Wednesday was the perfect summer day: sunny, breezy and warm. So, we went for a walk. It wasn’t until we returned to the office that it struck us: The streets of Lewiston were bereft of children.

Sure, there was the occasional adult moving hurriedly from one place to another and there was the shirtless panhandler looking for 72 cents – no more, no less. Only in Kennedy Park could we find children playing with each other.

An explanation appeared later in the day when we happened across an article in USA Today. The provocative premise: We may be witnessing something historic – the first indoor generation.

“The fundamental nature of American childhood has changed in a single generation,” according to USA Today. “The unstructured outdoor childhood – days of pick-up baseball games, treehouses and be home for dinner’ – has all but vanished.”

And, indeed, the premise is backed up not only by observation but by fact. You do see far fewer children outdoors these days and, when you do, they are often participating in scheduled activities supervised by adults.

Gone are the days of a kid riding lazily on a bicycle around city streets or through the park. According to the Centers for Disease Control and Prevention, 27 percent of children ages 9 to 13 play organized baseball, but only 6 percent play on their own.

With the shift among children to “media-related entertainment” – meaning it happens while seated in front of an electronic screen – there has been a precipitous decline in outdoor activities such as biking, walking, running, camping and swimming.

Bike riding alone, according to statistics cited by USA Today, is down 31 percent among children since 1995. “A child is six times more likely to play a video game on a typical day than to ride a bike…”

Visitor trips to national parks, and even Maine’s Baxter Park, are declining by the year. And even that staple of childhood, summer camp, is changing to reflect the more sedentary interests of today’s children. Instead of learning to canoe, hike or fish, many children now attend computer or even stock market investing camps.

One downside is obvious: In the 1960s, only 4 percent of children were obese; today 16 percent qualify.

But the “indoor generation” may suffer less perceptible effects. Will they be less in touch with the nature around them? Will that translate to less support for parks and conservation and more for highway building?

One CDC study finds that children who spend more time outdoors have longer attention spans than children who watch more TV.

While it probably doesn’t spell the end of Western civilization, it’s just sad that those lazy days of summer for many children are spent in a fantasy world rather than the real one.