Complex sentence: The express trackage east of the station was previously used for train storage but became an oft-frequented spot for the homeless; the tracks were cleared out in 1990, and false walls were installed at the east end of Second Avenue station to seal the tunnels.
Split into simpler sentences: The express trackage east of the station was previously used for train storage but became an oft-frequented spot for the homeless. The tracks were cleared out in 1990, and false walls were installed at the east end of Second Avenue station to seal the tunnels.