The only thing they’re sure of is it isn’t something in the water.

“That is the biggest concern of all, that there have been so many of these,” said Dr. Margaret Goodman, a neurologist and the ringside doctor who examined Johnson during the fight. “I think we need to evaluate the system from top to bottom.”

What is clear is that Johnson took a savage beating in a fight that probably shouldn’t have gone as far as it did, 38 seconds into the 11th round.

The 35-year-old fighter spent 16 years chasing a title, and finally won one on an upset in Italy in June. His reward was a $150,000 payday to defend his title on a pay-per-view card that included fighters with pedigrees such as Shane Mosley and Marco Antonio Barrera.

He fought valiantly, but was outclassed by Jesus Chavez, who rarely missed with punches that were thrown with bad intentions. Bill Johnson warned his son at one point he was going to stop the fight, but it continued until Chavez threw some two dozen unanswered punches and referee Tony Weeks finally called it.

Goodman immediately leaped into the ring to tend to the fighter. He said he was OK, didn’t have a headache and wasn’t dizzy.

“I’m just sad and disappointed,” Leavander Johnson told the doctor.

In a way, he was lucky. If another half hour had been wasted getting Johnson into the operating room, he likely would have died, just as 75 percent or more of fighters with such injuries do.

But something is surely amiss. Four brain injuries in four months in one city is four too many. It’s a wakeup call that blares at boxing regulators to try to find out why.

A good start might be brain scans before every fight, though promoters argue the cost would be exorbitant. As it is, no one knows if Johnson came into the fight with a brain problem, just as no one knows whether he was injured by a punch in the first round or the punches that finally ended the fight.

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“Maybe we can’t find the answer, but it’s something that has to be done and done very quickly,” Goodman said.

It’s too late for Johnson. All anyone can hope is that his brain responds when doctors eventually wean him off the drugs that induced his coma.

But it’s not too late for those who come after him.

Even in a hurt business, they deserve a little help.

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