ATCSCC put out a groundstop for ORD
due to it at 2120z, and 20-30 minutes later they put out a ground delay program for ORD
citing low ceilings as the driver...
I doubt it was a sinkhole, just a hole/crack in the pavement with some loose pieces. (There was also one on 13C at MDW
last week). They usually do a temporary patch job to get things running again, and clean-up the loose pieces (FOD hazard), and do the permanent repairs during the overnight hours.
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