Metro officials are continuing to investigate an escalator malfunction during Saturday's rally with Comedy Central stars Jon Stewart and Stephen Colbert.
Metro spokesman Steven Taubenkibel says four people were injured around 2 p.m. Saturday at the bottom of the escalator at the L'Enfant Plaza station downtown. He says it's not clear exactly how the escalator malfunctioned.
But witness Samuel Robfogel tells The Associated Press that the escalator accelerated suddenly. He says it appeared to be in "free fall" and that passengers on board were screaming.
D.C. Fire and EMS spokesman Pete Piringer says two men and two women were taken to hospitals. He says two of the injuries were considered serious by personnel on the scene, but none was classified as life-threatening.
The rally led to Metro's highest-ever ridership total for a Saturday, with about 825,000 passengers.