Entering the 21st century, progress continued despite several disasters. The September 11 attacks resulted in service disruptions on lines running through Lower Manhattan, particularly the IRT Broadway–Seventh Avenue Line, which ran directly underneath the World Trade Center. Sections of the tunnel, as well as the Cortlandt Street station, which was directly underneath the Twin Towers, were severely damaged. Rebuilding required the suspension of service on that line south of Chambers Street. Ten other nearby stations were closed for cleanup. By March 2002, seven of those stations had reopened. Except for Cortlandt Street, the rest reopened on September 15, 2002, along with service south of Chambers Street. Cortlandt Street reopened on September 8, 2018.