ELK GROVE (CBS13) – The cause of death for an Elk Grove boy remains a mystery. Aaron Nguyen collapsed at basketball practice Friday and was dead within the hour.

“They do the CPR on him and at that time I knew the worst thing happened to my son,” said Aaron’s father Andrew.

By all accounts, Aaron was a happy, healthy 12-year old boy. He was a straight “A” student who played the piano and trumpet, a huge Sacramento Kings fan and loved playing basketball.

Andrew says despite his son’s small size, he passed the first round of tryouts for his school’s basketball team. What Aaron lacked in size, Andrew said, he made up for in spirit.

“He made me proud, whatever he does,” Andrew said. “In the basketball league, he’s one of the smallest but the coach always put trust in him, call him one of the fancy players.”

His teammates and friends gathered at the school where Aaron collapsed at basketball practice the night before.

They released balloons and remembered the little boy taken away too soon.

“Whatever Aaron does, he always put 100% effort,” Andrew said.

Family and friends are gathering at the Aaron’s Elk Grove home to be there for his family during this devastating time.

“My wife is devastated,” Andrew said. “He never disappointed us at all,”

Aaron was on a private basketball team unaffiliated with the school district. He went to Toby Johnson Middle School, where grief counselors will be on campus Monday for students and staff.