When I heard this story yesterday it was quite alarming for me as a friend of mine is a monorail pilot and was working during the time of the crash. She's okay physically and wasn't involved in the crash, but emotionally she's upset and mourning the death of a co-worker.
The trains involved in the collision have been cleared off and the rest of the trains are up and running normally. It's not clear what happened to cause the crash. Several reports that I've heard is that one train was backing into the station to switch beams so it could go to the shop for the night, but didn't know about the train already in the station (or the train moved forward into the station as the other one was backing up). In any case, it's a sad event and my thoughts and prayers go out to the families affected by this tragedy.
It is fortunate that the crash happened at 2am- there was only one family in the train and no one other then the driver up in the front cab. If it had happened in the middle of the day, this accident could have resulted in many more casualties.