My father (Norman K. Johnson) once related a similar story; an early 1950's Los Angeles area fantrip sponsored by the ERHA of SoCal had chartered a LATL or LAMTA (ex-PERy) car and near the end of the trip that evening, a few wise-asses lined out a bridge over the LA river with some 30-40 torpedoes. The car hit them at speed, and the motorman didn't stop, so used to the usual railfan games. The most interesting thing was that the LAPD were shortly on scene down in the river, getting reports of multiple gunfire from the area. Probably the most unbelievable part of all this is that the LAPD did (!) find a shot up body by morning. I have no way of knowing how valid that part of the story is, so you can take it with a grain of salt. As for the first part of this story, I have absolutely no doubt of its genuineness, having grown up around the perifery of such people.