5:54 A.M. UPDATE: MARC Penn Line train 503 is experiencing mechanical problems in Baltimore and will be running express to the BWI station. It will be followed by train 405.
Meanwhile, MARC Brunswick Line train 870 is also running 10 to 12 minutes late approaching Germantown.
5:38 A.M. UPDATE: Train 503 is departing Baltimore about 10 to 12 minutes late.
ORIGINAL POST: MARC Penn Line train 503 is running 10 to 12 minutes behind schedule.