A San Jose State University student and aspiring rapper was taken off life support Saturday after becoming severely brain damaged when he went underwater and mysteriously stopped breathing during water polo practice last week, a university spokeswoman said Monday.

Ryan Harryman, 24, who grew up in Mountain View and went to Homestead High School in Cupertino, was set to graduate in May with a degree in anthropology. As a hip-hop artist, he went by the name 3PAC and gained an extensive fan group called the “Zero Hoots Gang.”

Harryman played on the university’s club water polo team and was at practice around 6 p.m. Tuesday at the school’s aquatic center when he began to struggle in the water, said Pat Harris, a spokeswoman for San Jose State University.

“Teammates noticed he wasn’t keeping up,” Harris said. “He then became submerged and was not breathing. It seems there was something that happened with Ryan. We’re trying to figure out what that was.”

Lifeguards pulled the unconscious man out of the water and began CPR before rushing him to San Jose Regional Medical Center. Harryman, though, suffered severe brain damage and life support measures were removed on Saturday.

“This is a tragic loss of a young man in the prime of life,” said university interim President Susan Martin. “Our San Jose State University community expresses its sympathy to Ryan’s family, friends and teammates.”

Investigators are looking into what led to the tragic accident. Harris said Harryman did not fall or hit his head during practice. On social media, many of the young man’s friends said he likely drowned.

“Though today was the saddest day of my life, it was beautiful to see you peacefully pass this afternoon with the whole family by your side,” Harryman’s brother, William Harryman wrote on 3PAC’s website Saturday. “The amount of love and support we have encountered these past few days is a true testament to how much you lived with love and not fear.”

Love and support has also been pouring in on social media where Ryan Harryman had cultivated a large audience of devoted fans of his music.

“RIP to the legendary silver back who originated the Zero Hoots movement,” the Zero Hoots Gang posted Friday. “Please keep his parents and the rest of his family in your thoughts and prayers and never forget the chedda daddy who started it all.”

Judy Cerda, a friend of Harryman who was in several of his music videos was devastated to learn of his death and said the two had been set to shoot another video on Saturday before the accident happened.

“It’s been really sad,” she said. “He loved having a lot of fans and the publicity. He took his rap seriously but liked to have fun with it too. Ryan was a gentleman — much different than his 3PAC character.”

The final post on 3PAC’s official website, zerohoots.com, is a YouTube link to the rapper’s last official video titled “Let’s F— Up Some Trouts (Get Chedda and Bread Son).

Evan Sernoffsky is a San Francisco Chronicle staff writer. E-mail: esernoffsky@sfchronicle.com Twitter: @EvanSernoffsky