I've been perusing the CBS, NBC, ABC, FOX news websites of many American cities every day for the past 20 years.
The first one I usually look at is the CBS News NYC website. It seems that almost every week (probably not that often) there's a story about somebody being pushed on the subway tracks without provocation by some other person. Of course, sometimes people are killed.
The person pushed on the tracks is almost always white, and the pusher is almost always black. I will allow that maybe I've missed one where the pusher was white, but I can't recall any incidents like that.
99+% of the pushers that I've read about have been black.
If people aren't looking around when they're getting ready to board a subway car, they'd better start.