More than two dozen children and several staff members were taken to a Pennsylvania hospital after a carbon monoxide leak was detected at an Allentown daycare facility.
The Lehigh Valley Health Network told WFMZ that the children it treated ranged in age from several months to 10 years old.
They all appeared to be suffering from different levels of exposure, officials said.
Capt. John Christopher told WFMZ that officials got a 911 call of a child becoming unconscious. When first responders arrived, they were alerted to the presence of carbon monoxide.
WFMZ reports that there was no carbon monoxide detector inside the building. An ordinance was due to go into effect later this month, requiring childcare centers to have a working carbon monoxide detector.
The daycare's director told WFMZ that she planned on installing one before the ordinance took effect.
It’s unclear what caused the carbon monoxide leak.
Common symptoms of carbon monoxide poisoning include headache, dizziness, weakness, upset stomach, vomiting, chest pain and confusion.
The Centers for Disease Control and Prevention said carbon monoxide poisoning causes 400 unintentional deaths in the U.S every year and over 20,000 emergency room visits.