DEATH AND crippling injury are constant companions of the professional boxer. Detached retinas, paralyzed limbs and early funerals are hazards of the punch-for-pay fraternity.

But fighters are not afraid. Probably because they can't afford to be.

To make a living with his fists, a man simply cannot let himself think of the possibility of being maimed or killed in the ring. Harboring such thoughts will keep a boxer from fighting well, or maybe at all.

But every now and then there's an event that makes us all mindful of the dangers of the ring. Such an event was the death 11 days ago of Willie Classen, who was knocked out in Madison Square Garden by middleweight Wilfred Scypion and died a week later.

According to Ring Magazine, 337 amateur and professional boxers were killed in the ring between 1945 and 1978. Classen was the eighth fighter to die this year.

Classen's death brings to mind the incidents of death and near-death I experienced in a boxing career that dates back to the '40s.

I was introduced to the smell of death in the prize ring at an early age. It was my first fight, 35 years ago at the age of 14 in the Meadowbrook Bowl in Newark, N.J. Heavyweights Larry Lane and Lem Franklin were fighting the main event. I was in the opening bout. I won my match and hurried back to ringside to watch the feature fight.

The going was rough, with neither fighter having the edge, when suddenly Lane tagged Franklin on the chin with a vicious left hook. Franklin went down.

They carried him out on a door that had been converted into a stretcher. He never got up on his own again.

A year later Lane fought a stablemate of mine, Teddy Randolph. Again Lane tagged his man with a wicked punch and Randolph went down.

But Randolph got up. He weathered an incredible strom of punches and came back to win the decision. I encountered Randolph in New York a few years ago. He appeared incoherent.

In 1946 a handsome welterweight named Jimmy Doyle, nee James Delaney, came to New York from California to seek his fistic fortune.

He defeated several journeymen in grand style and was considered by insiders to be the only welter around to effectively challenge champion Ray Robinson and No. 1 challenger, Tommy Bell.

For some reason, Doyle, who was also a poet, was matched with a hard-hitting middleweight named Artie Levine in Cleveland.

Levine, another stablemate of mine, was completely outclassed by the smaller Doyle until the last minute of the last round. Coming out of a clinch, Levine whistled a right against Doyle's temple, sending him crashing to the floor. His head hit the canvas with a thud and the doctors were in the ring trying to revive him before Levine could take off his gloves.

One of the doctors later commented that Doyle's heart had stopped beating for a few seconds while he was en route to the hospital.

Doyle survived, and six months later he was back in the ring.

Amazingly, Doyle whipped Tommy Bell despite the injuries suffered in the Levine bout. In June 1947, he was matched against champion Ray Robinson for the welterweight title.

I was fighting an eight-round semi-final on the card and became friendly with Doyle as we jogged around a park in Cleveland the last few mornings before the fight. I finally asked him over dinner the evening before the bout if he ever was fearful, especially after the Levine bout.

Doyle, a completely dedicated professional who was once observed practicing the same boxing move for five straight hours, replied pointedly And come he slow or come he fast, It is but Death who comes at last.

Doyle did well with Robinson for seven rounds. Then, without warning, he came out of an exchange throwing punches that a child could have avoided. He appeared to be boxing in slow motion. Something inside him had broken.

A suprised Robinson stepped back from one of the slow pokes and dropped Doyle in his tracks with a vicious left hook. He never regained consciousness.

I had to go on next.

I was fighting a hard puncher named Mike Berskovitch. He tagged me in the second round, with a hard right I never saw. I went down for only the second time in my career. My head cleared by the time I got to one knee at the count of two. The referee stopped the bout. I protested.

"One killing is enough for tonight," the referee said.

I didn't share the referee's concern that I might get killed or maimed. I was smart, I thought. I wouldn't be like Lem Franklin and Jimmy Doyle. I was different. I was smarter. Yet there I was arguing with the referee not to stop the fight. Maybe it was pride. But there was a strong urge to keep fighting, no matter the consequences. I knew fear, the feeling of being vulnerable, but felt I could handle it.

Laverne Roach, a handsome ex-Marine, didn't know the meaning of the word fear. He always was willing to gamble in the ring. He had a can't-miss look about him.

I sparred with Roach each day for two weeks while he was preparing to fight the exciting Tony Janiro. Chatting while awaiting our turn in the ring at Stillman's gym, I came to like Roach.

He was a devout Christian who wanted to be champion. I remember envying his outlook and absolute certainty that God was going to see to it that he won the title.

He upset Janiro and was soon matched with the great French middleweight, Marcel Cerdan. The Frenchman brutalized Roach for seven rounds before putting him away in the eighth. It had been a man against a boy.

Later Roach was matched with still another stablemate of mine, Georgie Small. Small was a strong man and had a heavy punch.

The two went at it for most of the 10 rounds when Roach suddenly slumped to the canvas. The effects of the beating by Cerdan and now the heavy blows of Small were too much. He never regained consciousness.

Sonny Boy West was probably the first fighter to die in the ring before a national televsion audience.

West was an outstanding lightweight in the early '50s and was clamoring for a title match with Ike Williams. The two finally met on national TV and fought like lions for several rounds. Then Williams began to take West apart.

West could be seen bleeding profusely from the nose and mouth as he answered the bell for the eighth round.

West was met at midring by Williams, who struck him savagely with a combination of punches that put him down for keeps.

The ring fatality that drew the most public ire occurred in the bout involving then welterweight champion Benny Kid Paret and challenger Emile Griffith.

Paret had had several wars in just a few months before and after winning the title. He was then matched with indestructible middleweight Gene Fullmer, who proceeded to knock him senseless after first hitting him with at least fifty right hands that never were answered.

Paret was then matched with Griffin for the title. As usual, Paret fought hard and well but it was apparent that he was wearing down when Griffith cornered him and pinned him to the ropes with an incredible series of punches.

It was only when Griffith stepped back to get a breath that Paret made that unmistakable slump to the canvas. He too never regained consciousness.

Men had died in the ring before, but none had been champions fighting before a national audience of some 25 million people.

The questions were: Why didn't the referee stop the bout? How come he was allowed to fight so soon after suffering such a beating from Fullmer? Why should boxing be allowed in the first place?

By the time Rocky Marciano was in his prime, the various commissions had set up some safeguards, like enforced vacations for fighters who are knocked out.

Marciano did cripple the promising Carmine Vingo in a brawl, but, unlike his colleagues, Vingo was helped financially by Marciano. Others were less fortunate since there was no fund for crippled fighters.

The fate of boxers has been better lately, but that could be because there has been so much less boxing to begin with. Since the emergence of Muhammad Ali on the scene in 1960, the game has at least appeared to be cleaner, more competitive and more humane.

Still, it took the corner men of challenger Joe Frazier to stop the Thrilla In Manila in the 15th round. Frazier, in the tradition of the game, was ready to go on. But his people wisely stopped the match. Ali, the most instinctive of athletes, said afterwards, "There was the smell of death in that ring with us tonight." Frazier escaped, thanks largely to his corner men.

But there will always be corner men like the one that worked one of my fights.

This cynical cigar chewer listened quietly while I explained that I was in no shape and that I could not go on much longer since the guy I was fighting was giving me no rest. He was on me like a tiger all night.

This went on for three more rounds, me taking a licking and coming back to the corner complaining that "this guy is not giving me rest. I'm in no shape . . . I don't know what to do."

No answer from the cigar chewer.

Finally, it appeared that I really couldn't go on. The corner man listened again to my litany as he patched up the cuts.

And when I said, "I don't know what to do," he replied as he gave me the shove off the stool: "Think of something fast, kid. Here he comes again."