ROSEMEAD ( — Popular MMA fighter Joe Camacho died suddenly on Monday, one day after fighting in a match, shocking fans and friends alike.

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Camacho, 41, died at Queen of the Valley hospital in West Covina after he began experiencing difficulty breathing. He had taken part in a competition in Long Beach on Sunday.

The MMA pioneer and Brazilian Jiu-Jitsu instructor had opened a school of his own this year, and a vigil was held Monday night by fans and students.

“Good guy, who really cared about the community,” student George Valdez said. “I’ve got to stress that so much, because a lot of people become something and they forget where they came from. Not Joe.”

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Gathered students, as well as those who grew up knowing Camacho, praised his work as an instructor.

“He taught us how to win and lose,” friend Orlando Aspericueta said. “And every time we lost, we still won.”

While coroners have not identified the exact cause of death of the former Featherweight, the possibility of a heart attack has not been ruled out.

Camacho’s family is unaware of any outstanding health issues that may have led to Camacho’s unexpected death.

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“I’m so proud of him for who he’s become,” fiancee Maggie Arechiga said. “His last words to me were ‘I love you’.”