from Qantas.com :
Karratha Aerodrome has closed today Monday, 22 September 2008 due to unscheduled runway works. At this stage all flights into and out of Karratha today will be cancelled.
Qantas is doing all possible to get our customers to their final destination as quickly as possible.
Please refer to the Arrivals and Departures pages for up-to-date flight information. If you have any questions regarding your booking, call Qantas on 13 13 13.