Commuters on the N, R, and D lines found themselves plunged into subway hell this morning when the MTA quietly introduced surprise service changes on the Monday morning rush hour.

Turns out, Monday was the first day of planned maintenance that will continue for roughly the next year, during which Bay Ridge and Sunset Park N trains will run local between 36th and 59th Streets in Brooklyn. Tacking two stops onto a subway trip is not an unbearable inconvenience in and of itself, but the MTA failed to warn anyone about the construction in advance, and signal problems made the situation far worse.

Some subway riders experienced delays of over an hour, even as the agency's website advertised "good service" and its Twitter account claimed "no reported incidents along the line" around 8 a.m.

City Councilmember Justin Brannan, whose represents Bay Ridge, languished on the R train along with many of his constituents. After contacting the MTA, he confirmed that there will be "long-term structural repair work that will cause the N to run local between 59th and 36th stopping at 45th and 53rd. The issue this morning was that the signals were not properly configured for this change. The MTA swore that the hot mess we experienced this morning will not happen again even though the service change on the N will remain in effect. It just sounds like the MTA wasn’t ready for prime-time this morning."

Brannan also faulted the agency for not informing commuters in advance:

Frustrated Bay Ridge resident Monica Parks reports that she boarded her hell train—a northbound N that should've been running express—at the 8th Avenue stop in Brooklyn at 7:50 a.m. Typically, her trip to work in Harlem takes an hour and 15 minutes; today, it took over two hours. She says she and her fellow passengers proceeded to sit for 20 minutes in between stations, with the train progressing at a snail's pace to 59th Street and then 53rd.

This unscheduled stops surprised Parks, who had seen none of the customary signs advertising a substantial service change. With the train stalled, Parks says the conductor blamed "train traffic." During the hour it took her train to crawl toward the Manhattan Bridge, Parks said some riders got so tired of standing they simply sat on the floor.

Straphangers tweeted at the MTA for answers, but even though one furnished photographic evidence of a blue wall blocking off the track ahead, those answers were not forthcoming. Parks reports that she only "got the full story" when the MTA tweeted an explanation at 10:30 a.m.

In a statement, NYC Transit Chief Customer Officer Sarah Meyer said, "Today was the first weekday of a long-term structural rehabilitation project in Sunset Park, due to be complete in July 2019. We had issues and challenges coordinating internally and the planned change was not properly communicated to our customers."

According to Meyer, the shitshow was compounded by an "error" that kept the D from running express at 36th Street, and left the N, R, and D wildly congested. In the future, riders should plan on local N trains between 36th and 59th Streets. Regular express service resumes on the N and D north of 36th Street, and the MTA's sites have been updated.

"The significant delays our customers experienced this morning in the project area will not happen again," Meyer vowed, "and we estimate that the planned work will only add up to five minutes of additional travel time during the weekday rush hour periods going forward."

"We deeply apologize for our significant errors today and know that we need to do better. We are working through our policies and procedures to ensure this does not happen again."

It's just about time for the evening rush, so we'll soon see if the MTA can keep its promises.