Over 20 people were injured at Club Deep Blue on Brainerd Road when the rear deck collapsed, sending partygoers on a six-foot drop.
Deep Blue security personnel told Chattanooga Fire Department officials that a large group of people was on the deck waiting to enter the building when the deck collapsed.
Fire crews assisted Hamilton County EMS with approximately 23 people. Those hurt primarily had leg, ankle and back injuries.
Those with more serious injuries were taken by ambulance, while a CARTA bus was called in to transport the remaining injured to area hospitals.
Chattanooga fire marshals and a city building inspector were called to the scene to assess the damage.