Inspectors walk the 660 miles of track in the New York City subway system twice a week. Specialized trains with sensors, cameras and computers run the rails checking for problems.
But after a serious derailment on Friday on the F in Queens, the MTA has been stepping up checks.
Two rail defects were discovered Tuesday on the express track near 36th Street in Astoria and on the D line in Brooklyn near 62nd St.
The track inspection train located the problem in Queens. Routine checks turned up the issues in Brooklyn. Repairs were made.
Rail conditions, as they are called, happen regularly in the system.
The MTA is continuing to identify rails from the same batch that derailed on Friday. Those areas are being tested now.
An MTA spokesperson says there have been no issues with those specific rails.