The transit agency announced about 2:30 p.m. that normal rail service had resumed after water was pumped from the station. Shuttle buses had been available for passengers to reach the station, while trains bypassed it for about seven hours.
The Washington Metrorail Safety Commission announced that it has requested an investigation into the flooding.
Peter Golkin, a spokesman for the Arlington Department of Environmental Services, said that just before 10 a.m., crews determined that the broken water main was on a line that belongs to Metro.
The pipe that ruptured funnels water to the station, where it is used primarily for facilities that include station manager restrooms, Stessel said. Water will remain shut off through the weekend, and portable toilets have been brought in for workers.
As a result, the Pentagon station’s north escalators will be closed through the weekend to accommodate the rental toilets, which have been put nearby, Stessel said. South-side escalators and all elevators will remain available.
“All things considered, if we had to pick a day for something like this to happen, this is not a bad one from Metro’s perspective,” Stessel said. “It’s a busy travel day for highways and airports and Amtrak, but not so much for Metro.”
Stessel said Pentagon engineers stopped the flow of water into the station by turning off a valve. He said the station was largely cleaned up by 11 a.m.
Images and video posted to social media showed people walking through the water at the station. On social media, riders had plenty of comments.