When I was getting qualified for freight service around Cambell Hall (NY) back in 1985, I made a number of qualifying trips on NJ Rail passenger trains that took me in/out of Hoboken terminal.
Hoboken is "an end of the line" terminal -- that is, the tracks end in a bumping post. Trains generally operate with the cab control car on the east end (bumping block), and locomotive on the west end.
Trains come through the Pallisades tunnels and emerge at the throat of the terminal (controlled by [appropriately] "Terminal Tower" which stand in the middle of everything. Then they work their way through the switches and into the platform tracks.
It's been more than 30 years, but I recall the track speed through the tunnels being 50 or 60.
Emerging from the tunnels, the signal system would almost certainly drop to 30 through the throat of the terminal ("medium speed" is 30, train would probably be getting "medium approach" or "approach")
The last signal the engineer would get (before entering the station platform track) would be a "restricting", with either a 15 or 20mph limit.
You non-railroad folks are probably gonna be hearing a lot about "positive train control" in news stories about this over the next few days.
I'd seen this in action on my later days (on Amtrak), but if I recall correctly, these systems are generally TURNED OFF in most congested terminal areas, because speeds were slower and because -- if left implemented -- it would seriously snarl operations (as to why would require a much longer post).
In terminals and congested stations (such as Penn Station and Grand Central Terminal in NYC), the ptc will govern train operations "on the approaches" to the terminal, but once you enter the actual terminal tracks, it will either switch off automatically, or the engineer will [temporarily] disable it.
At that point, it's up to the engineer to control the train up to the final stop. The speeds aren't high in these situations (under 20mph), and the operator is presumed competent to be able to work his way across the switches and signals and get the train platformed and stopped.
My reckoning is that the engineer of the train in question was doing fine (or at least "getting by") through the tunnels and entrance to the terminal, kept the train under control until about the time he got by the last signal to the platform. Then something went wrong. He might have been tired (some of these morning commuter jobs start EARLY), or something else health-wise. Nodded off, zoned-out, or worse.
.... and ran right through the bumping block.
I'm also going to guess that when the event recorders are checked (on control cab car and on engine), they'll indicate a speed of 20mph or so. The lead car looks like it made it past the block onto the concourse (and perhaps even into the waiting area). That's about right for 20mph or even just 15. If that train had been going much faster, there would have been more damage.
Not sure what can be done to prevent instances such as this in the future.
Of course, I can predict what might be proposed, such as inbound trains being forced to make a "safety stop" at the entrance end of the platform track, and then start up again and proceed to the block. But in a busy terminal during rush hour, trains operate on very short "headways", and have to be kept MOVING.
Forcing them to stop/start to get to the platform is going to make folks' morning commute somewhat.... longer.
In the end, it's up to guy up front running the locomotive.
It's as simple as that.
