There were a whole series of collisions where the NTSB identified the crashworthiness of commuter cars as an important factor. That led to an FRA study and, eventually, new standards.
The MARC-Amtrak collision in Silver Spring Maryland in 1996 was an important part of this as well. In that crash eleven lives were lost. The NTSB found that several of the victims survived the initial impact but then were killed in the subsequent fire. This was because the structural damage of the lead passenger coach (the MARC cab car) made it impossible for the occupants to escape. The end doors were crumpled and jammed shut and they were unable to open the emergency windows
That appeared to me to be an important feature of the Fairfield crash. Despite several of the cars being heavily damaged it appeared the doors could still be opened.
In the NTSB report for the MARC-Amtrak collision in Silver Spring (link
) investigators said when they reported the emergency windows could not be opened, at first MARC officials doubted that was true. The NTSB had a MARC official go into a coach and try and pull open the emergency exit window. The rubber sealing around the window was so weather-rotted the MARC official found, to his surprise, he could not get the window out.
Following that crash Metro-North and all other commuter agencies had to inspect the emergency exit windows in all cars. They were also required to put instructions on the interior door control cabinets (how to open the sliding doors by hand in an emergency) and use fluorescent paint. I vividly remember seeing that happen.
The M8s appear to be very well-designed and the engineers who designed them should be high-fiving one another! They probably are.