NEW YORK - A jammed subway car door and signal problems brought the morning commute to a grinding halt for thousands of straphangers Thursday morning.

The Metropolitan Transportation Authority says the mechanical issue involved an L train at the Bedford Ave. station.

The agency says part of the train was outside the station and that riders were being removed.

Social media accounts of the service problems between Brooklyn and Manhattan began appearing around 8 a.m. showing platforms crowded with unhappy riders.

Trains started rolling again about an hour later with residual delays.

Around 10 a.m., a problem with the line's signal system stopped trains in their track from Eighth Avenue to Rockaway Parkway.

Service was restored roughly a half later with residual delays.