Reports from Washington are starting to suggest that the automation system was in fact at fault in the cash of the DC Mtro train crash that killed nine and injured 70. Example, near the bottom of a report by  Fox/AP:

Federal investigators said Thursday that Metro’s signaling system failed to detect a test train stopped in the same place as one that was struck during this week’s deadly crash.

Test results indicate the oncoming train involved in Monday’s crash may have lacked information that another train was stopped on the tracks ahead.

This would be consistant with the reports we got that the Mushroom had indeed been deployed.  It likely would ahve been deployed sooner but for the first train being behind a bit of a blind turn, as I indicated in my discussions of the matter at OTB the other day. If I’ve got the spacing correct, she hit the brake about halfway around the turn when the first train became visible… far too late to stop the thing in time, even assuming the brakes were working… and that’s not been established yet.