I have heard of the massacre of Chinese miners at the hands of the white Union Pacific miners, in fact I think it was quite a common thing, Union Pacific for example were very good at preventing the white miners from forming Unions and protesting for better pay, you can see why these things happened, the railroad companies called the shots, if the white workers didn't knuckle down and accept low pay then all the railroad had to do was bring in cheaper labour (Chinese mostly) I guess that the white workers needed a scapegoat and cheap Chinese labour was the obvious target.