An ammonia leak at an O'Hare International Airport terminal suspended Blue Line service between O’Hare and Rosemont Thursday morning on the CTA, transit officials said.



The Chicago Fire Department confirmed the leak, but it wasn't immediately clear whether anyone was evacuated at the airport.



The O’Hare terminal closed at 8:55 a.m. after the leak was detected, according to reports. The Chicago Fire Department was on site.



CTA spokeswoman Lambrini Lukidis said the agency is stopping Blue Line trains in Rosemont, and busing passengers to and from the airport.



Lukidis says the CTA has not been given any indication of when the station will be allowed to reopen.



Check back for more information on this developing story.