The phrase "gruesome scene" refers to a situation that is extremely shocking or unpleasant to see, often because it involves violence or something horrific. Full definition
After a few adjustments to the bus's faulty video player, a small monitor begins to display gruesome scenes of the aftermath of the fire at the reactor. (discovermagazine.com)
As several analysts who, in fact, watched the videos have pointed out, this particularly gruesome scene never occurred. (broadly.vice.com)
During very gruesome scenes I had to walk away from the book and then return to it after a break. (bookbrowse.com)