Antwun Echols, the hard-hitting middleweight contender who challenged twice for a world title, died Sunday, July 2 at the age of 52.

The news was first reported by local outlets in his hometown of Davenport, Iowa, where he died. The cause of death was not announced.

Known as “Kid Dynamite” because of his explosive and unpredictable style, turned pro in 1993 after becoming the 1992 U.S. Olympic alternate at 156 pounds behind future world champion Raul Marquez. His pro debut would be an inauspicious affair as he was knocked out in the first but Anthony Ivory, a club fighter whom he outweighed by 13 pounds. He recovered from the loss, winning 22 of his next 24 fights to earn an IBF middleweight title shot against Bernard Hopkins in 1999. Echols stunned Hopkins early with right hands – even dropping him unofficially during a referee’s break – but lost a unanimous decision.

After winning two straight, including avenging the loss to Ivory, Echols got a second shot at Hopkins on HBO in December of 2000, losing by tenth round stoppage in a rough, foul-filled bout.

Echols returned to the ring the following year as a super middleweight and met Charles Brewer in what would become one of the wildest comebacks in recent boxing history. Down twice in round two, Echols hurt Brewer the following round and scored a TKO win in the third round. The win kicked off his career-best run, winning five straight before getting an opportunity to face Anthony Mundine in Australia for the WBA “regular” super middleweight title. Echols lost a close but unanimous decision, and would soon begin to decline.

His final record of 32-22-4 (28 knockouts) is not indicative of his true standing as a fighter as he went 1-19-3 from 2005 until his final bout in 2016. His later years were also marred by two shooting incidents in which he was shot on separate occasions in the arm and leg. The latter incident in 2007 also led to Echols being arrested for possession of crack cocaine and outstanding warrants for child support issues, according to the Associated Press.

In a 2013 article for the Quad City Times, Echols admitted that he took some of those fights without proper training and in weight classes that were too big for him in an effort to earn money for his family. When asked by that same reporter how many children he had, he answered “23, I think.”