The Hoboken-bound Pascack Valley Line train pulled into Anderson St at about 8:20am. I went out about 2 hours later, saw the train, and that police had blocked off the street from Park St to Linden Ave.
All the passengers were off the train (first picture). At that point, I didn't know what had happened, so I asked one of them. He said he heard something about brake problems. Another engine had shown up to pull the train and they were in the process of coupling it (second picture.........I HAD to include that billboard).
When that was done, passengers were let back on the train (third picture).
I left a few minutes later. The train was still there, but I'm sure if left shortly thereafter and service was restored in both directions.