When Crazy Earl lifts a bunny-shaped teddy toy in a ruin in Full Metal Jacket, a booby trap is activated and he dies. But how was that explosion able to kill him? He didn't lose any blood for example.
Based on this post-production script treatment from the Kubrick Archive, the impact of the explosion caused Earl to become unconscious and stop breathing:
75 INT. BOMBED FACTORY--DAY The patrol moves carefully through the gutted shell of a building. The clink of their gear as they walk sounds loud in the unnatural silence.
CRAZY EARL stops to pick up a child's stuffed toy.
BANG! The toy triggers a booby trap, blasting CRAZY EARL across the room. The squad dives for cover.
COWBOY: Face outboard and take cover! Do it!
DOC JAY scurries up to CRAZY EARL, who is unconscious and gives him mouth-to-mouth resuscitation. COWBOY scrambles up to them. He looks at CRAZY EARL. Then JOKER runs in.
Given the visible symptoms and total lack of obvious injury; e.g. blood and viscera, this would seem to imply that he was killed by overpressure force trauma from the explosion or possibly (and more mundanely) by hitting his head as he fell.
In general, primary blast injuries are characterized by the absence of external injuries; thus internal injuries are frequently unrecognized and their severity underestimated ... Thus, the majority of prior research focused on the mechanisms of blast injuries within gas-containing organs/organ systems such as the lungs, while primary blast-induced traumatic brain injury has remained underestimated. - Wikipedia: Blast Injury
This isn't a gory scene in the movie, but just a simple plot point to show how easily you can get promoted during the war.
The explosion that kills Crazy goes off behind him, and Crazy lands on his side. The medic arrives and flips him onto his back.
If there was any visible damage. I guess it's implied that it's on Crazy's back which we can't see from the angle of the camera.