CHICAGO (CBS) — Travelers are still having a difficult time flying into and out of Midway International Airport as hundreds of flights have been canceled for the past few days after two control tower employees tested positive for coronavirus.

Sen. Dick Durbin says the tower was closed to keep other workers safe.

RELATED: Southwest Airlines Reduces Flights At Midway Airport, After Air Traffic Control Tower Closed Over COVID-19

“When I spoke to the head of the Federal Aviation Administration he told me there was a similar challenge at another major airport. I’m afraid we haven’t heard the last of it. It’s an indication of what happens when someone tests positive in a work atmosphere that is a critical part of our economy and the safety of our nation,” he said.

(CBS)

Durbin hopes the tower will be able to resume operations early next week after a thorough cleaning.

The move resulted in more than 173 canceled flights on Friday, and Hawthorne said the airline is averaging four to six flights an hour.

The air traffic control tower at Midway was closed Tuesday evening, and operations for Midway were moved to the Chicago TRACON radar facility in Elgin, after the tower workers tested positive for coronavirus. At the time, the FAA said airport operations would continue at a reduced rate until the situation was resolved.

CBS News reports the airport was moved to a “one flight in, one flight out” approach for flights. Arriving and departing pilots will announce themselves over a common radio channel, essentially the same procedure for how one would fly into a municipal airport without a tower. Once airborne, pilots will communicate with Chicago TRACON, an FAA radar facility in Elgin. Departures will organize by departure time, and hold short of the runway until the arriving plane clears. Then the first one up will announce and take off.

The FAA’s longstanding contingency plans call for services to fall back to Chicago TRACON in the event the tower goes dark. TRACON is the regional air traffic control hub that controls airspace after a plane leaves the main tower’s immediate vicinity.