FBI investigating Metra 'sabotage'

The FBI says it's investigating the "sabotage" of a section of Metra tracks on Chicago's South Side.

Officials say Metra employees noticed 12 missing railroad spikes on Monday. The spikes hold down metal plates that bind the rails to wooden ties underneath.

Metra notified police and federal authorities, including the Department of Homeland Security and the Transportation Security Administration, which investigates threats to planes and trains.

FBI spokesman Ross Rice says agents are checking into a possible connection to a domestic violence case involving a Metra engineer.

The affected tracks carry three commuter lines, including the Metra Electric Line to University Park and Blue Island, and the South Shore Line to Michigan City and South Bend, Indiana.