Finn hides his nose and mouth in his elbow, closes his eyes, and bows away against the cloud of debris. To say he was shocked would be an understatement. It all happened so fast that he didn't even have time to yell out in panic.

He looked back up again, actually missing the Stormtrooper helmet for once, and tried to look through the dust. "Where did that come from!?" It sounded like the noise had something to do with it.

... In retrospect, he thought it was probably dumb to yell right now.