Officials in Brooklyn said a loud bang triggered fear inside the Barclays Center early Sunday following a boxing event, injuring more than a dozen people. According to Pix 11, the audience mistook a loud noise outside the arena for a gunshot. When they heard the noise, the gathering of fans who had gathered to see Gervonta Davis and Rolando Romero fight panicked. People were shoving and pushing one another, resulting in some people being trampled.

Many spectators even tried leaping onto the ring in fear. Some attendees were detained by security until it was considered safe to depart. Police eventually determined that no shots were fired. According to an FDNY official, 18 people were hurt in all. Nine of the victims required medical attention at local hospitals.

Tennis star Naomi Osaka was among the crowd at Barclays Center. She expressed her fear on Twitter, stating “I was just in the Barclays center and suddenly I heard shouting and saw people running, then we were being yelled at that there was an active shooter and we had to huddle in a room and close the doors, I was so f*****g petrified man.”