Asbestos concerns prompted the Federal Aviation Administration to send a portable control tower to Tulsa International Airport.
It should be fully operational sometime Friday.
Until then, air traffic controllers worked from the ground floor of the current tower. Because of that they're only able to operate one runway.
The trouble at the tower started Wednesday when a contractor using a solvent to remove tiles created fumes that forced workers to abandon the top floor.
Environmental experts said the fumes are not hazardous, but the airport is waiting for air sample tests before giving the all clear.
The airport did release a statement Thursday regarding the air quality, saying:
“Environmental consultants analyzing the air quality of Tulsa International Airport's air traffic control tower have determined that the facility's air quality tests below detection limits for any hazardous particles. The consultant gathered 10 total samples, five in the tower cab and five in the tower break room.
The tests were conducted during the early morning hours following a request from the air traffic controllers union for assurance that the air quality in the tower was safe for controllers. On Wednesday, controllers were evacuated from the tower because of fumes generated from a cleaning solvent used by a contractor removing floor tiles.
Aircraft operations have continued at TUL throughout the day on Thursday with minimal disruption. Airport officials are now waiting on the FAA and NATCA to determine when the upper level of the control tower will resume operation.”