This the first time that I observed the results of a derailment other than on my layout. Today, a LIRR passenger train derailed and sideswiped another train on the west side of the interlocking just before (50 feet) the Jamaica station hub. Evidence of one car sideswiping another was quite apparent. The side of the car looked like it was one of two automobiles that swiped each other. Not twisted metal, but it sure was scratched and dented along the side of the car. Someone must have thrown a switch before the train cleared the switchpoint and the next to last car hopped out. It jumped laterally and the wheels that belonged on the left rail wound up on the right rail with the car leaning over. If it had tipped over with passengers, there would have been serious injuries. When I left, there were two old RS-ancient diesels hooking up the front of the train and a maintenance thingy approaching the rear, to pull out the last car. They will then have to do whatever they do to lift and move the damaged car. Three of the eight passenger tracks were closed for service. I do not envy those people trying to get home tonight since the three tracks that are down are on the generally eastbound side of the station. It is so much easier to solve problems on the Lessons Learned Line.