New York City transit authorities cautioned on Tuesday that the city’s subways may be closed for several days thanks to Hurricane Sandy. Several tunnels had flooded, switches had been damaged, and the South Ferry station was “track to ceiling” with water, according to officials. “The New York City subway system is 108 years old,” said Joseph Lhota, the chairman of the Metropolitan Transportation Authority. “It has never faced a disaster as devastating as what we experienced last night.” There is one silver lining, however. It doesn’t appear that Hurricane Sandy caused any permanent damage to the system.