"Execute Order 66."

Supreme Chancellor Sheev Palpatine, a.k.a. Darth Sidious, triggers Contingency Order 66 for the Grand Army of the Republic, commanding the clone troopers to turn on and assassinate their Jedi commanders as part of his self-coup against the Galactic Republic. In a series of shots, Commander Cody has an AT-TE fire on Obi-wan Kenobi on Utapau, and Ki-Adi-Mundi, Aayla Secura, Plo Koon, and Stass Allie are gunned down from behind by their clone escorts. These are intercut with shots of Jedi Grandmaster Yoda clutching at his chest as he feels the deaths of thousands of Jedi across the galaxy through the Force. Finally his own troops on Kashyyyk get the message and prepare to attack... only for Yoda, forewarned by the deaths of the other Jedi, to turn the tables on them and escape.

Example of:
Atrocity Montage