Derailment on New York subway 27 June 2017

Try reading the whole article, the fourth paragraph states that "At least 34 people were injured" but only "17 transported to local hospitals for treatment of minor injuries".  Pretty standard for a derailment.  The "improperly secured piece of replacement rail" reminds me of the 2007 Bethnal Green derailment where improperly stored equipment was the cause, 20 people were injured of which 8 were taken to hospital.

Rather than "passengers milling about on the tracks" as the caption under the photo suggests that appears to be a controlled detrainment with a member of staff or the emergency services in a hi-viz jacket shining a torch at the track to assist the passengers.

One passengers says that a door was torn off in the crash which would have allowed passengers to access the track as the New York Subway is like the LU Sub Surface lines. There were passengers on the track after the 7/7 bombings at Edgware Road and Aldgate but passengers wouldn't be able to access the track in deep level tunnels as there's not enough room between the train and the tunnel wall.

As for Tube passengers forcing doors to escape a "fire" on a train just watch the video of the 2013 Holland Park incident. Panic!!!!!!!!!!!!!!!!

Unless there is something different about the braking systems of NY subway trains I cannot see how an emergency brake application could cause a derailment.