of this project, the NYCTA project to lengthen IRT stations to accommodate ten-car trains would be complete. Work on the platform extension project took place in 1965 and 1966. During the project, old tiling and mosaics were removed and replaced with the 1970s-style varnished, tan-colored brick tiles. One of the mosaics was preserved in the New York Transit Museum. In 1965, Cortlandt Street west of Church Street was demolished to create the superblock of the World Trade Center. The station, with entrances at Vesey Street and inside the World Trade Center concourse, was separated from the remaining block of Cortlandt Street. During the 1980s, when service levels across the subway system were decreased greatly from their heyday in the 1910s, the Metropolitan Transportation Authority installed the system's first train-frequency schedules at the Cortlandt Street station. Older timetables and maps elsewhere had been removed since they had become inaccurate. Trains bypassed the station in the aftermath of the February 26, 1993, World Trade Center bombing. Soon after, 1 trains were back to Chambers Street. In 2001, just prior to the September 11 attacks, the Cortlandt Street station saw 19,446 riders per day. September 11, 2001, attacks The station and the surrounding subway tunnels were severely damaged in the September 11, 2001, terrorist attacks following the collapse of Two World Trade Center, resulting in the closure of the line south of Chambers Street. During the September 11 attacks in 2001, a train operator reported an "explosion" to the MTA's Subway Control Center one minute after the first plane struck the World Trade Center's North Tower at 8:46 a.m. Subway service was halted shortly afterward and, as a result, no one in the subway system died. The steel I-beams of the station were crumpled and the station roof collapsed, as the tunnel had been located underground, relatively close to ground level. The original tunnel had measured wide and high, with columns between the two tracks spaced at intervals of . Soon after the attacks, two options were considered: either the existing line would be repaired, or the tunnel would be diverted westward just to the north of the World Trade Center site before heading to a new terminal at South Ferry. The first option was chosen, and to quickly restore service to Rector Street and South Ferry stations to the south, workers demolished the remainder of the station and built walls where the