Amtrak service has been restored between D.C. and Baltimore at restricted speeds.
Passengers should expect residual delays, but Amtrak says all scheduled trains were expected to operate Friday afternoon.
The delays were caused by sagging overhead power lines that caused some trains to be canceled Friday morning and delayed others.
Maryland Transit Administration spokesman Terry Owens says the problem occurred around 7:30 a.m. Friday near Baltimore-Washington International Thurgood Marshall Airport. He says the power lines became entangled with part of a MARC commuter train and began to sag.
The train became disabled, and crews were working to get it moving again. All subsequent MARC trains on the Penn Line were halted. The Camden Line, which uses different tracks, was not affected.