MURFREESBORO, Tenn. (AP) — One person was killed and another injured in a shooting after a high school graduation at Middle Tennessee State University, according to police.

Police confirmed the shooting Wednesday night after the Riverdale High School graduation at Murphy Center, an on-campus arena. Authorities said the ceremony for 450 seniors had already ended and people were leaving when the shooting occurred outside the arena near a tennis court.

A 17-year-old was arrested and charged with first-degree murder Thursday afternoon, Murfreesboro police said.

The person who died was identified by authorities as 18-year-old Hasani Brewer.

The injured victim, also 17 years old, was not identified. He was in stable condition Thursday afternoon, Murfreesboro police said. It was not immediately known if the victims were students.

Police said a preliminary investigation shows Brewer and the 17-year-old victim got into a fight, which spilled over to the tennis court next to Murphy Center after the end of the evening commencement ceremony.

The shooter opened fire, killing Brewer and injuring the 17-year-old, police said.

“This was not a random shooting,” police spokesman Larry Flowers said. “The two victims and the shooter knew each other.”

Rutherford County Sheriff’s Office Sgt. Dan Goodwin called the shooting a tragedy, adding, “We mourn with the family who lost a loved one and the victim injured.”

Rutherford County Schools spokesperson James Evans said the school, about 35 miles (55 kilometers) southeast of Nashville, was closed on Thursday as a precaution.

Rutherford County School Board members held a moment of silence Thursday morning while meeting to interview three candidates for director of schools. Board member Claire Maxwell read a statement, WTVF reported.

“My heart is breaking for the victims of last night’s tragic ending to Riverdale graduation. What should have been the greatest night of their young lives instead turned into everyone’s worst nightmare. My thoughts and prayers go out to the young life lost and his family and my prayers are also extended to the other young man critically injured,” she said.

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