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Thomas "Hitman" Hearns, left, clarified his statement that former middleweight champion Marvin Hagler, right, was in an ICU after receiving a coronavirus vaccine.

Hagler died suddenly on Saturday at age 66.

Hearns, who is among boxing's legendary "Four Kings" alongside champions Hagler, Sugar Ray Leonard and Roberto Duran, asked fans for prayers for Hagler in an Instagram post.

"A real true warrior Pray for the king and his family.. he's in ICU fighting the after effects of the vaccine! He'll be just fine but we could use the positive energy and Prayer for his Full Recovery!"

The news media slammed "anti-vaxxers" for repeating Hearns' suggestion that Hagler suffered an adverse reaction to the vaccine.

Somewhere in the mountain of media denials was a report that Hagler died from "natural causes."

But people who die from natural causes are terminally ill and/or expected to die.

Hagler's wife, Kay, announced his passing on Facebook, saying his death was not expected.

"I am sorry to make a very sad announcement. Today unfortunately my beloved husband Marvelous Marvin passed away unexpectedly at his home here in New Hampshire. Our family requests that you respect our privacy during this difficult time."

Hearns, 62, chastised anti-vaxxers in a statement to London's DailyMail.com.

"Our love and respect to Marvin and his family, this is not an anti vaccine campaign.. it's outrageous to have that in mind during the passing of a King, Legend, Father, Husband and so much more."

However, his original post is still up on his Instagram page.
 

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Legendary boxer "Marvelous" Marvin Hagler passed away after suffering side effects of the mRNA vaccine he received days before. He was 66.

Hagler's wife, Kay, announced his death on Saturday.

Former boxing champion Thomas "Hitman" Hearns tweeted on Saturday that Hagler was in a hospital intensive care unit after suffering side effects to the vaccine.

"A real true warrior Pray for the king and his family.. he's in ICU fighting the after effects of the vaccine! He'll be just fine but we could use the positive energy and Prayer for his Full Recovery!"

Boxing fans were shocked at the news. One fan tweeted:

"Im proper gutted!! the Great Marvin Hagler dies after taking the vaccine! Please do your own research before making a decision on putting something in your body that has not been tested properly & we r being used as the guinea pigs & not told the #Truth about #vaccine."

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Hagler was the undisputed middleweight champion of the world from 1980 until 1987. He recorded 52 knockouts during his stellar career.

Among his knockouts was a memorable brawl with Hearns in April 1985 at Caesars Palace in Las Vegas, which Hagler won by third-round knockout (watch the first round below).