The R train's Montague Street tunnel closure began Friday night.
A subway tunnel that shepherds hundreds of thousands of New Yorkers between Brooklyn and Manhattan will be shut down for 14 months because of damage caused by Superstorm Sandy.
The R train's Montague Street tunnel closure began Friday night. The train is used by an estimated 650,000 daily straphangers.
Metropolitan Transit Authority officials say the tunnel was submerged by 20 feet of water after Superstorm Sandy struck.
They say that for 10 days after the late October storm, corrosive salt water damaged tracks, cables and other equipment.
Riders who use the R train's Brooklyn-Manhattan tunnel will have to find alternatives. The authority is not adding alternative lines.
The MTA says the R train will run on weekends over the Manhattan Bridge. On weekdays it will not run between the boroughs.