Massacre at Dachau by US Army

Interesting. (Warning: Graphic Death scenes)

I've read a lot of WW II history over the years and this is the first time I've read it.
US army troops machine-gunned 350 Waffen-SS combat troops (including wounded and sick) in cold blood after liberation of Dachau. According to the link, they mistook the Germans for CC guards. I wonder if this was classified and withheld from the US public.