I'm guessing that this is similar to an accident that occured on Superman: Ride of Steel back in 2001.
"(Monday, August 6, 2001) - At Six Flags New England theme park in Agawam, Massachusetts, twenty-two people were injured after two roller coaster trains collided on the park's Superman Ride of Steel roller coaster. The accident happened in the loading station as one train was preparing to be dispatched and the other was returning to unload passengers. Reports indicate that the second train failed to stop and struck the stationary train at about 20 miles per hour. Both trains sustained damage in the crash.
Twenty-two passengers were taken to local hospitals, all with minor neck, back and facial injuries. In addition, two or three riders were knocked unconscious in the crash.
The ride has been shut down pending an investigation by state and local authorities. Park officials and representatives from the ride's manufacturer, Intamin AG of Switzerland, are also investigating."
That was a news report from that accident. I believe they found something wrong with the magnetic braking system.[/QUOTe
A couple of points:
1. This incident seems different from the one's at WDW were it seems a ride malfunction is the cause.
2. Superman in NE (as I seem to remember from past reports) has had several problems (some extremely serious). Personally I have more faith in Disney rectifying this than I do Six Flags.
3. That stop at the end is abrupt normally so I can only imagine how bad it is getting hit from behind by another vehicle. If you have never been on it, you come into that area very quickly and get stopped very fast. A car behind you coming in behind you and colliding with you that fast would not be pleasant.