Metro isn't the only transit system having problems with escalators.
On New Year's Eve 2007, 11 people were hurt in Atlanta when an escalator malfunctioned inside a subway station. The escalator was a Westinghouse Modular 100 -- the same model involved in the recent accident at the L'Enfant Plaza station.
Amateur video posted on YouTube shows riders falling at the bottom of the escalator and one person handing a baby to safety over the handrail.
After that incident, Atlanta's transit authority shut down most of its escalators for inspection and found that 84 of 149 needed repair work, according to the Washington Post.
The Modular 100 design was discontinued decades ago, but is still widely used in the Metro system. The Washington Post said 489 of the system's 588 escalators are that model.
Mechanics have been inspecting all of Metro's 588 escalators. More than 100 escalators have been pulled out of service for repairs.