Amtrak service was temporarily suspended between Newark and New York City because of mechanical problems with the Portal Bridge.
A Midtown Direct train was headed into New York when it broke down around 8:30 a.m., officials said.
Amtrak officials are eyeing an electrical substation in Richmond, Va., as the possible source of a voltage problem that halted trains between New York and Philadelphia.
Gov. Chris Christie killed plans for a Hudson River tunnel, but now he wants money for a bridge over the Hackensack River.
New Jersey Transit says it has reopened one of two tracks that were closed by wire damage on its Northeast Corridor rail line.