8:27 A.M. Update:

Due to congestion caused by Penn Line train 408, train 410 is running 30 to 35 minutes late. Train 421 is running 45 or more minutes behind shcedule.

8:03 A.M. Update:

Train 408 is on the move and approaching New Carrollton station 30 minutes late, according to the Maryland Transit Administration. Train 410 is still expected to run 15 minutes late following that train and an Amtrak train.

Original Post:

Big MARC delays for Penn Line riders: Train 408 is having mechanical problems, so a rescue train is bringing it back to Union Station. Passengers will be transferred to other trains.

This will cause train 410 (scheduled to depart Washington at 7:45 a.m.) to run about 15 inutes behind and severely delay train 421 (departing Baltimore at 8:10 a.m.).