The next time you get a chance to see a clip of Nick Robinson’s game-winning basket at the end of the Stanford-Arizona game, focus less on the moment, and more on the aftermath.

It happens in a flash. Robinson rises, shoots, scores . . . and is immediately buried beneath tons of euphoric humanity as fans storm the court in celebration. Pay close attention. See if you don’t wind up thinking what I’ve been thinking as I see that clip over and over:

How long until someone gets hurt real bad in one of those things?

In Tucson, the answer is: five days ago.

That someone is Tucson High School player Joe Kay, who punctuated a big win last Friday night with a two-handed dunk. At game’s end, Kay was tackled by exhilarated fans who came rushing out of the stands. Their exhilaration cost him dearly; he suffered a fractured jaw and a torn carotid artery.

The tear in the artery caused diminished blood flow to his brain, inducing a stroke that has left Kay partially paralyzed. He is reported to be improving, though still in intensive care.

Kay, who turned 18 Saturday, is a 4.0 student and a National Merit Scholarship semifinalist who has accepted a full volleyball scholarship to Stanford. How much of his seemingly limitless potential he will be able to fulfill at this point is unclear.

Robinson was infinitely more fortunate. After being buried alive he joked, “A couple of people were on top of me in places that were rather uncomfortable.”

He wasn’t the only one feeling discomfort. The wife of former Stanford quarterback Jim Plunkett hurt her foot when she got caught up in the human tidal wave. There had to have been others. Watch the clip. The potential for injury is enormous. Tiger Woods was there, with his fiancee. More to the point, so were thousands of sons and daughters and cousins and friends.

So was Arizona coach Lute Olson, who has seen a thing or two in his 900 games as a college basketball coach — including the near-riotous celebration of his own fans after a victory over Stanford in Tucson five years ago.

“You read about these things happening in Europe and South America at soccer games and such, fans going nuts,” Olson told a Tucson paper. “At Stanford I had never seen a group like that come out like they came out. Fans get emotional. You don’t have control over fans as much as you have over teams and what they do.”

In fact, there is no controlling over fans when they decide to participate in mass madness. It’s the frightening open secret of big time sporting events.

Storming the court and taking the football field have been expressions of unbridled joy for years, to the point that a new generation of collapsible goal posts are being developed in the hopes they will reduce the likelihood of catastrophic injury in the event of a postgame pigpile.

Managing the event can help to an extent. But only to an extent. When Cal and Stanford fans almost rumbled on the field after a Big Game a few years back, a Stanford official admitted that no matter what precautions are taken, “If the fans want to take the field, they’re going to take the field.”

At least a cyclone fence stands between the football field and the stands at Stanford Stadium. Fans at basketball arenas have full and immediate access to the court whenever they want it.

A big win or fast finish usually does it. Several years ago, St. Mary’s defeated Villanova in a game at McKeon Pavilion. When the final buzzer sounded, the stands emptied onto the floor.

I was sitting at courtside, and before I could get out of my seat, students were rushing past me and climbing over the press table on their way to the court. For 10 or 15 highly disconcerting seconds I was virtually defenseless to knees in the back and elbows to the head as waves of otherwise reasonable people threw reason to the wind.

“Uncomfortable” only begins to describe the feeling. And here’s the kicker — it was an event little noted nor long remembered. Just another Dickie V. moment at a college basketball game near you.

The frightening open secret isn’t all the way out of the closet, but it’s making steady progress. Watch the clip. All the ingredients are in place to bring about the day when we wonder how such a euphoric moment could lead to such tragic consequences.

They know too well in Tucson. It begins innocently enough.