10 questions for Metro about the L’Enfant tragedy

The National Transportation Safety Board said there was a critical breakdown in communications and poor coordination among subway workers during the smoke incid (Video: Jason Aldag/The Washington Post)

Several basic questions remain unanswered about Monday’s Metro tragedy in which Yellow Line rider Carol Glover died and more than 80 other passengers were taken to area hospitals — two in critical condition.

Metro General Manager Richard Sarles apologized for the incident and expressed condolences for the victims, but he and other Metro officials have refused to answer any questions about why a train abruptly stopped , went dark and filled with smoke in a tunnel in downtown Washington, citing the investigation by the National Transportation Safety Board.

Here are 10 unanswered questions for Metro officials:

1. What caused the train to stop before riders and the operator saw the smoke?

2. What did the train operator do after he noticed the smoke?

3. Did the train have power? If so, why didn’t the operator back up into the station?

4. Who called D.C. Fire and EMS and how long after the train stopped did this happen?

5. At what point was power to the third rail cut and who did it?

6. How long did D.C. firefighters have to wait before being allowed to enter the tunnel?

7. How long were passengers trapped on the train?

8. What did the Metro operations control center know and when did it know it?

9. Were all the cars in the same state , with smoke and scared passengers?

10. Was the smoke toxic?