Metro-North train service was partly restored by Tuesday morning, nearly three days after the Metropolitan Transportation Authority shut down all public transit in New York because of Hurricane Irene. But several lines remained down, and the Port Jervis Line was expected to be crippled for months.

The MTA Web site said the Hudson and New Haven commuter rail lines and the lower part of the Harlem Line began running normally for the Tuesday morning rush hour. The Pascack Valley Line, which begins at Spring Valley in Rockland County and connects to a New Jersey Transit line in Bergen County, was also expected to reopen sometime on Tuesday.

There's still no service on the New Canaan, Danbury and Waterbury lines in Connecticut and the upper part of the Harlem Line. The worst news, however, was on the Port Jervis Line, which runs south through Orange and Rockland Counties in New York and then connects to a New Jersey Transit line that runs through Bergen County to Hoboken.

Heavy flooding caused catastrophic damage to the tracks, bridges and signal system, according to a Metro-North statement, and service wasn't expected to be restored to the line for months.

The Port Jervis Line is devastated, Howard Permut, the president of Metro-North, told the Times Herald-Record in Middletown, N.Y. The magnitude dwarfs anything we've ever seen before in our history, and it will take months to fix.

Many sections of the line were still under several feet of water on Tuesday, with floods in some station parking lots as deep as 15 feet.

Permut told the Times Herald-Record that materials to repair the washouts have already been ordered, but a more difficult fix will be the 50-year-old signal system. He said parts aren't readily available for the obsolete equipment and will have to be hand-fashioned.

Permut said budget constraints wouldn't stop Metro-North from making the necessary repairs. The real problem is the amount of time it'll take.

In the meantime, the roughly 2,300 passengers who commute via the Port Jervis Line every day will have to find alternative means of transportation. Metro-North said it would run buses roughly on the normal train schedule, with more buses running as road conditions improve. Port Jervis Line tickets will be cross-honored on the Newburgh-Beacon ferry or bus, which would allow riders to take the Hudson Line into Manhattan. Tickets will also be cross-honored on Hudson Line trains.