A dangling cable in the tunnel at Woodley Park station on Metro’s Red Line caused delays of up to 30 minutes for commuters Wednesday morning.

The incident began just before 8 a.m. Riders reported crowded platforms and trains as trains shared a track between the Dupont Circle and Van Ness stations during the morning rush hour on the system’s busiest rail line.

Metro spokesman Dan Stessel said the cable is a “communication cable” and he did not know “why it became dislodged.”

“The concern is that a passing train could have snagged it and pulled it down,” he said.

Just after 10 a.m., Stessel said crews had been working to fix the cable and he expected the situation to be resolved within the next 30 minutes.

Trains were unable to pass safely on part of Metro’s Red Line because of the cable hanging over the inbound track.

Throughout the morning, Metro’s information varied on how long the delays would last. The agency said at one point they would be 20 minutes, then later raised it to 30 minutes.

At 10:21 a.m., Metro sent an e-mail alert saying that trains were no longer sharing a track but that delays continued in both directions of the Red Line.

The problems on one of the system’s busiest commuter corridors, sparked an avalanche of frustrated posts on social media sites:

Correction: An earlier version of this post incorrectly stated that the track problem was outside Union Station.