Twenty-seven people were taken to hospitals with severe to moderate injuries after a carbon monoxide leak at a Pennsylvania, U.S. day care home Tuesday morning, fire officials said.
The Allentown day care had at least 25 children and eight staff members inside.
Happy Smiles Learning Center in Allentown had 25 children and eight employees at the time, according to Allentown Deputy Fire Chief Christian Williams.
The day care was evacuated, officials said.
Crews from UGI Utilities responded and shut off the gas line outside the building as a precaution, UGI Utilities spokesman Joe Swope said.
Williams said the cause has not yet been determined. According to Swope, UGI believes the leak was caused by a faulty heating unit and a blocked ventilation system.