BALDWIN: A fairly serious incident Monday is raising questions about the city's emergency response. One person died, and more than 80 others were treated after this tunnel filled with smoke. It happened at the busy Metro station near the National Mall. A lot of federal employees hop off there as well. A number of passengers had to escape walking along the tracks. Let's go to Washington to Joe Johns. Joe, as far as the city and response go, what have you learned?</s>JOE JOHNS, CNN SENIOR WASHINGTON CORRESPONDENT: Well, Brooke, this was far and away the worst incident in years on the D.C. subway system caused by thick smoke produced by something authorities call an electrical arcing event. The National Safety Board is investigating. One dead and 80 taken to the hospital for smoke inhalation. Political leaders are asking for answers, including Mark Warner, of Virginia. He called it a nightmare situation and, in a letter, demanded a full letter from the Washington Metro Rail Administration, so it's probably going to be a long investigation -- Brooke?</s>BALDWIN: What are people saying? If you're saying this was an electrical arcing event, heaven forbid, what it could be the next time. I hear you on this letter from Senator Warner, but what are other concerns?</s>JOHNS: The question that was asked at the scene, still asked today, the system's evacuation plan. What took so long for people in one of the trains to get out of the tunnel and into fresh air where they could breathe again? By some estimates, it could have taken 20 to 40 minutes for people to evacuate.</s>BALDWIN: Wow.</s>JOHNS: There were reports people were told by the operator of the train to remain on it, even though they could have walked to safety. There also appears to be a communication problem with first responders, too. There's some suggestion firefighters arriving on the scene were not actually told immediately that there were still people down in the tunnel. So it raises a question of whether the subway system is prepared in the event something even worse jumps off. There would be implications for other subways around the country.</s>BALDWIN: Incredibly scary. Joe Johns, thank you.
Questions over D.C. Subway Response