BOSTON (CBS) – Boston Celtics star Isaiah Thomas’ sister was killed Saturday morning in a Washington state crash.

A Tacoma woman was killed around 5 a.m. Saturday morning in Federal Way, Washington when her car veered off of Interstate 5 and crashed into a jersey barrier.

Family friends told KIRO-TV the woman killed in the crash was 22-year-old Chyna Thomas, who is the sister of the Celtics guard.

Celtics guard Isaiah Thomas' sister, Chyna Thomas, was killed in a Washington state crash. (Image Credit: Washington State Patrol)

The Celtics confirmed the news Saturday night in a statement.

“We are terribly saddened by the tragic loss of Chyna Thomas. The thoughts and prayers of the entire Celtics organization are with Isaiah and his family,” the team said.

NBA Commissioner Adam Silver also released a statement following the tragic news.

“The NBA family mourns the tragic passing of Chyna Thomas and we send our deepest condolences to Isaiah, his family and the Celtics organization during this difficult time,” Silver said.

Isaiah Thomas was born in Tacoma, Washington and attended the University of Washington.

State Police in Washington said Chyna Thomas was not wearing her seatbelt at the time of the crash.

The Celtics begin their first round playoff series on Sunday against the Chicago Bulls.

Chicago reacted to the news of Chyna Thomas’ death on Twitter on Saturday.

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A league source told Mark Murphy of the Boston Herald that Isaiah Thomas did not find out about his sister’s death until after Saturday’s practice.

“He’s in shock,” the source told Murphy.

Murphy also reported the team may not know until game-time if Thomas will play in Sunday’s playoff opener.