Updated 4/29/2011 at 5:30 p.m.

CHICAGO (CBS) – A senior at Marist High School in the Mount Greenwood neighborhood has died, after collapsing on the school’s basketball court Thursday night.

Paul Simmons, 17, of the 11900 block of South Princeton Avenue, was playing basketball with his teammates and teachers during the “senior lock-in” event at the school, at 4200 W. 115th St. The event lasted from 9:30 p.m. Thursday to 6 a.m. Friday.

His parents say they could hardly process the news of Paul’s death, especially after just seeing him happy and healthy a few hours earlier as he left home for the school event.

“He came and hugged and kissed me, said ‘Mama, I’ll see you in the morning,’” his mother, Vera Angion-Simmons, told CBS 2′s Mai Martinez. “This was not even on our mind at all as far as my son getting sick and not coming back home.”

He collapsed on the court while playing, and was taken to Advocate Christ Medical Center in Oak Lawn, according to the school.

“As he was playing in the middle of a game, he just dropped over, and of course we called 9-1-1,” principal Larry Tucker said.

 Simmons was pronounced dead at the hospital soon afterward, according to the Cook County Medical Examiner’s office, which later attributed the youth’s death to a heart condition known as hypertrophic cardiomyopathy.

Simmons was set to attend Spring Hill College in Mobile, Ala., as a student athlete in the fall.

Basketball was the young man’s passion, his father says.

“He slept it. He dreamed it. He talked it,” Paul Simmons Sr. said.

Funeral arrangements are pending.