Train service along Amtrak's Northeast Corridor came to a halt Sunday morning when an overheard power line collapsed at the century-old bridge over the Bush River near Aberdeen.

At 11 a.m., Amtrak reported that repairs were under way but warned passengers traveling between Philadelphia and Washington to expect delays of up to four hours.

An Amtrak spokesman said both north- and southbound passengers were being moved to diesel trains while the electric cable is repaired.