UPDATE: At 11 a.m., earlier track issues were resolved and normal service was restored.
On Wednesday morning, Metro warned riders to expect delays on the Blue and Yellow lines due to a cracked rail near the Pentagon station.
The transit agency said trains were sharing a single track early Wednesday on the Yellow line between the Pentagon City and L'Enfant Plaza stations, and on the Blue line between the Pentagon City and Arlington Cemetery stations.
Metro said delays of 20 to 30 minutes could be expected during the morning rush hour.
At 7:30 a.m. on Wednesday morning, Metro also reported problems on the Red Line. Due to a track problem near Takoma, trains are single-tracking between the Fort Totten and Takoma stations. Metro estimates a.m. delays there of 20 to 30 minutes.