Emergency responders work on the scene of a carbon monoxide leak at a day care center in Allentown, Pa. on Tuesday, Oct. 11, 2022. (Zach DeWever/WFMZ-TV via AP)

ALLENTOWN, Pa. (AP) — An apparent carbon monoxide leak at a Pennsylvania day care center has sent about two dozen children to the hospital. Officials say none of the injuries are considered serious. Emergency responders went to the Happy Smiles Learning Center in Allentown on Tuesday morning on reports of an unconscious child. Authorities say the building was evacuated after air quality detectors worn by firefighters were triggered. The 25 children were being evaluated at the hospital, and all were listed as stable. Eight staffers were also in the building. The cause of the leak is under investigation.