Witness Ryen Aleman was watching a game at the tournament in Jacksonville when he saw the shooting and heard a barrage of gunfire.
Aleman said he ducked to the ground and crawled to the restroom while everyone ran for safety.
"As I was going in the restroom, I stayed in there, and I just heard -- there was just so many gunshots, at least 20 of them at the most," said Aleman, who traveled from Texas to play in the tournament.
He said the shooter may have had a laser to assist his aim on the gun.
"I’m still shocked, I can hardly talk," Aleman said.