At the bidding of Sha-kym Adams' sister, members of the Minneapolis South High School football team let go of the heart-shaped balloons they clutched Thursday afternoon.

Some balloons floated up and away across Lake Nokomis. And some landed in the tree around which the memorial for Adams had sprung up, settling in the branches like ornaments.

Adams, 15, drowned Wednesday while cooling off in the south Minneapolis lake with teammates after a morning football practice. His death off the 50th Street Beach was the first lake drowning in Hennepin County this summer, according to the Sheriff's Office.

On Thursday afternoon, about 100 of his family, friends and teammates gathered at the beach for a vigil in his honor.

Adams' sister, Shawnte Mikulak, 24, said the 15 balloons marked "15 marvelous, wonderful, unforgettable years."

"My brother was my world," she said.

Adams, who was about to start his sophomore year at South, was a wide receiver on the football team. He was among seven teens who were exercising and swimming at the beach Wednesday morning, said Lt. Art Saunders of the Sheriff's Office.

The other boys told police that a group of them was swimming to a floating dock when he suddenly cried out for help, then disappeared. After an intense search that included Adams' friends, passersby and several law enforcement agencies, County Water Patrol divers using sonar equipment found his body in about 15 feet of water shortly after noon.

Nokomis' main beach, on the lake's west side, is staffed by lifeguards almost continually. The east-side beach where Adams drowned is staffed from 11 a.m. to 7 p.m. Thursdays through Sundays, so there was no lifeguard there Wednesday, although several from the larger beach across the lake rushed over to help when they heard emergency vehicles.

Kimberly Adams, Sha-kym's mother, emphasized Thursday that his friends shouldn't feel guilty, that her son's death was an accident. She said they had done what they were supposed to by using the buddy system while swimming, "which means he did not die alone." She added that her son knew how to swim and had swum in deep water before.

"Hug your children," she said to the crowd at the vigil. "Tell them you love them, and children, tell your parents you love them."

Sha-kym's father, Sharrod Rowe, speculated that his son might have become tired while swimming.

The lanky teenager loved Cedar Point and McDonald's double cheeseburgers, his father said. His favorite restaurant was the Brazilian steakhouse Fogo de Chao. He loved playing catch, football and tennis.

"He was special," Rowe said. "He was going to be somebody. He is somebody."

Adams was a fan of animé and video games, his friends said.

Someone once called him "Daddy Long-Legs," said C.J. Bostwick, one of Adams' closest friends, who will be a sophomore at Edison High School this fall.

"He tried his best to look on the bright side of things," Bostwick said.

Jessica Velez, who will be a sophomore at South, said Adams was in theater class but wasn't the best actor. But it didn't matter, she said, because he always had a smile on his face.

'He led by example'

Before leaving the vigil, members of the South football team stood together around the memorial and chanted, "South family."

Though Adams was only a sophomore, head football coach Lenny Sedlock said he was already an involved, committed member of the team.

"Just by showing up on the field, he led by example," Sedlock said.

School District Superintendent Bernadeia Johnson said in a statement that the district is providing support to students and staff. Families are encouraged to call the high school at 612-668-4300 for assistance, she said.

The school's football booster club said it has established a fund to help Adams' family with expenses. For more information, go to www.gofundme.com/cpge7g.

Star Tribune staff writer Paul Walsh contributed to this report. Beena Raghavendran • 612-673-4649