The Federal Aviation Administration temporarily closed the air traffic control tower at Chicago Midway Airport Tuesday, after three of the agency’s technicians tested positive for the coronavirus.
The agency confirmed there was a ground stop in effect at Midway Tuesday evening. Under a ground stop, flights are held at their point of departure.
The FAA said the airport is open, and that operations would continue at a reduced rate until the tower reopens.
Earlier Tuesday, the FAA noted the Midway tower had been cleaned according to Centers for Disease Control and Prevention Guidelines.
In a statement, the National Air Traffic Controllers Association said it has asked the FAA to close the tower “until it can be disinfected according to appropriate public health standards.”
Southwest spokesman Ro Hawthorne acknowledged there were “several delays” for both arrivals and departures at Midway across all airlines Tuesday evening.
Midway Airport late Tuesday said via a post on Twitter that “operations will be limited until further notice.”
The flight problems are extending into Wednesday’s flights, with Southwest canceling nearly 180 flights to and from the airport, according to flight tracker FlightAware.
Southwest said travelers need to check their flight status.
Midway is the second-busiest hub for Southwest Airlines after Baltimore-Washington International Airport. It is the dominant carrier at Midway, with 245 daily departures.
The airport saw 22 million passengers in 2018, according to the most recent data from the Chicago Department of Aviation.