The investigation into Monday's subway crash continues. More distubing details are coming out...Were the brakes past due for inspection? Did the emergency brake fail when the operator tried to use it? Was the train completely in automatic mode at the time of the crash - and if so, why didn't the computer system stop it? Finally, and maybe most disturbingly, the NTSB urged the Washington Metropolitan Area Transit Authority (WMATA) to modernize its subway cars in 2006 - a move that would have improved the cars' crash worthiness. Why wasn't that done?
At 9:15 Heidi will press NTSB Spokeswoman Debbie Hersman for answers to all of these questions. Make sure you watch.
And click on the comments button below to share your thoughts on Monday's crash.