system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does someone die from an explosion?

Like is it the heat, or shrapnel, or could it be the initial impact?
gpt
Explosions are of different types. 

1. Ones where you see a big fire ball... These are only used in movies mostly and only have cool looks on their side... They are the most harmless variety. Their fire only appears for a few seconds and quickly extinguished. They have low temperature flames so they don't set fire to anything around them.

2. incendiary explosions. They have persistent high temperature flames that cover a wide area of the explosion.. they set objects on fire and can be very lethal in closed places. They kill be inflicting high degree burns on the body.

3. Anti personnel or shrapnel explosives.. they are what you generally find in military use. They are the deadliest when you compare the damage to explosive ratios.. they have inbuilt shrapnel inside them that gets launched by the explosion... They are nothing fancy to look at, you only get to see a flash and smoke raising.. but the sharpnel travels tens of thousands of feet per second and causes puncture wound across the body.. people very near to the point of origin will also be damaged by the shock wave..

4. Shock wave damage... This type usually requires a very large amount of explosives.. it has high damage that's very difficult to avoid but the explosion is highly inefficient at killing.. you need great amount of explosives to do significant damage.. they occur in gas line leakage, factory accidents or high explosives weapons and can launch a shock wave that can damage for miles.. the shockwave basically compresses and expands the internal organs in the body.. if the wave is strong enough, it ruptures the organs.. in this explosions you will often find that the body is intact or with severed limbs with seemingly no puncture injuries... However, we can find that most of the innards are turned into a mushy paste. They are particularly dangerous in enclosed spaces. They are some cases where people walk away from the explosion seemingly unharmed only to collapse and die a few minutes later. Common injuries among the survivors include hearing loss, ruptured intestine, cerebral hemorrhage and retinal detachment.