Officials feared the brackish storm water that poured into tunnels could corrode vulnerable signal and switching systems, complicating the task of reopening a bus and rail system that ferries 8.5 million passengers on a typical workday.

WSJ: Superstorm Sandy Cuts Wide Swath of Damage

Officials feared the brackish storm water that poured into subway tunnels and onto tracks could corrode vulnerable signal and switching systems, adding to the time workers will need to reopen the MTA's full system, which ferries 8.5 million passengers on a typical workday.

WSJ: Buses Back, But Subways Could Take Days Longer