CHICAGO (CBS) -- Chicago Transit Authority Blue Line trains were disrupted during the afternoon rush Wednesday after a train hit a bicycle on the subway tracks downtown.

The train hit a bicycle at the Clark/Lake stop. There was nobody on the bicycle, which had somehow ended up on the tracks through means unknown.

Trains headed west to the West Side, Oak Park, and Forest Park were standing at the station as a result of the obstruction. Other westbound trains were experiencing delays, as trains in each direction were running on one track.

Passengers were boarding on the O'Hare-bound side at the Grand, Clark/Lake, Washington, Monroe, Jackson, and LaSalle. Shuttle buses were also set up between Jefferson Park and Grand.

This was the second disruption involving a Blue Line train on Wednesday alone. Just before 11:30 a.m., a person was struck and killed by a Blue Line train near the Austin station on the boundary of Chicago and Oak Park.

Trains were stopped during the investigation, but later resumed. The person's death was believed to be a suicide.