The Naugatuck fireworks display ended early Thursday night following a significant malfunction, according to police.
Police said a detonation at ground level was the reason for the problem. There were no injuries.
Fire officials and investigators determined that the remaining fireworks had to be discharged in order to be safely disposed of, police said.
The remaining fireworks were detonated around midnight.
Police say the cause remains under investigation.
No injuries were reported in the incident, police said.