LITTLETON, Colo. -- Five Columbine High basketball players gathered on a home patio court to shoot hoops as they struggled to grasp why their close friend and teammate committed suicide.

Junior Greg Barnes, 17, who lost one of his best friends and saw a teacher die in last year's Columbine bloodbath, hanged himself Thursday while classmates went to school, said neighbor Leonard Purer.

''I do not know if Columbine caused this, but I do know he was upset by it. All the students were upset by it,'' said Purer, who has known the family for nine years.

A CD, set to replay continuously, blasted a song by the group Blink 182 with the lyrics, ''You'll be sorry when I'm gone,'' and ''I never thought I'd die alone,'' said teammate David Mitchell, an exchange student from Melbourne, Australia.

''I talked to him the night before, and it didn't seem like anything was wrong,'' he said Friday as he took a break from the game on teammate Brian Deidel's court. ''We talked about the usual stuff, girls.''

Deidel, also a childhood friend of Barnes, said, ''I just didn't believe it. It was horrible. It made me mad. Mad at Greg.''

Grief counselors cautioned against automatically linking Barnes' death to the Columbine shootings, noting teen-agers cope with a great deal of pressure. Suicide is the third-leading cause of death for people ages 15 to 24.

Barnes' death came just two weeks after the anniversary of the massacre. It was the second suicide among friends or relatives of the victims since October, and the latest in a series of tragedies that have sent the Columbine community reeling.

Investigators would not say whether Barnes left a note and gave no additional details. Six counselors came to Columbine on Friday, and substitute teachers were on call to fill in for staff members who wanted to stay home, said Jefferson County School District spokesman Rick Kaufman. Many students skipped school.

''It's a somber mood at Columbine High School,'' said Kaufman, who declined to give details about the death.

The sheriff's office and the Jefferson County coroner also declined to provide details. ''Some things should remain confidential to the family,'' Coroner Nancy Bodelson said.

On April 20, 1999, two teen-age gunmen killed 12 Columbine classmates and a teacher and wounded 23 people before committing suicide in the worst school shooting rampage in U.S. history.

Barnes was in a science room when the gunmen opened fire. He told Sports Illustrated he saw teacher Dave Sanders ''take two shots, right in front of me'' as he watched the rampage through a window in the door. Barnes was also a good friend of victim Matt Kechter.

Since the massacre, most in the Columbine community have lived with grief as a constant companion.