ALLENTOWN, Pa. (AP) – A carbon monoxide leak at a Pennsylvania day care center has sent more than two dozen children and several adults 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 children and adults were evaluated. Eight staffers were also in the building. Investigators say the leak was caused by a malfunctioning heating unit and a blocked venting system. (Photo: AP)