First posted to the Chinese-language video sharing site YouKu, this clip appears to show a People's Liberation Army grenade training session that nearly ended tragically.

When the trainee lobs his grenade too low, it bounces off the lip of the reinforced trench. He dives for cover on the spot and, seconds before detonation, his instructor yanks him into the safety of a nearby foxhole.

After the trainee scampers away, the instructor casually inspects the blast area as if, just maybe, this isn't his first cadet-with-a-bad-overhand experience.