On July 23, NTSB announced that the track circuit at the accident site had been malfunctioning since 2007,18 months prior to the collision, and WMATA has since found six other circuits within the system that have been behaving unusually.
The track circuit at the accident site had been malfunctioning since 2007 to the collision. This was 18 months prior. This was what NTSB announced on July 23. WMATA has since found six other circuits within the system. This was on July 23. This system have been behaving unusually.