The Harrisonville Aquatic Center is back to business as usual after it went on lockdown Tuesday afternoon. According to the city, a boy dressed in all black and wearing a Kevlar vest walked along the fence of the pool holding a rifle-style Nerf gun. From a distance, swimmers and lifeguards thought the gun was real. Allison Scavo was at the pool on Tuesday with her son. She said they had just gotten inside when it turned to chaos. “All of a sudden lifeguards started yelling to get out of the pool,” Scavo said. “There was panic, and kids weren’t running as fast as they should have, so they just started saying there is a man outside with a gun.”She said everyone rushed inside one of the buildings at the aquatic center. Inside, people locked and barricaded the doors. Others consoled scared children.Police arrived minutes after receiving the call. “Once they arrived, they were able to locate the individual and it was determined that the gun that was called about was actually a Nerf gun,” Daniel Barnett, the Public Information Officer for Harrisonville, said. “They were able to take the individual into custody. Everyone was safe and there were no injuries.”He said the boy cooperated with the police and did not resist arrest. Barnett said he is proud of the way the staff at the pool and police department responded to the situation – saying it's important to respond to everything as if it is a real situation. “Our staff jumped on it quickly. As soon as a threat was realized, they moved to get everyone inside, get the doors shut and build up barricades,” he said. “We have to be more safe than sorry because at the end of the day, if we don’t respond properly, people’s lives are at stake and that’s not something we are going to leave up to chance.”He said it was a sigh of relief for everyone once officers realized it was a Nerf gun. This is what the Nerf gun looked like:“We are very grateful this wasn’t a situation where a person was out intending to do harm,” Barnett said. Charges have not been filed against the boy. The city is still investigating. No one was injured.