Hazmat crews responded to a carbon dioxide leak at a chemical plant in Aston Sunday night.
The leak closed Pennell Road between Somerset Lane and Concord Avenue for a couple of hours. The road was reopened around 10 p.m.
Emergency crews arrived at a dance studio connected to the plant after several people reported a foul odor.
The studio was evacuated and several people were treated for breathing problems.
The plant was closed. Officials are investigating the cause of the leak.
