[Joe 6-pack]

That had to be one pretty powerful device. This is what a tightly gathered group of ~100 people looks like:

If you can imagine a blast radius that would be lethal to 90 of them, and then wound an additional 200 beyond that...just damn.

For comparison, there are many stories where a selfless soldier or Marine throws himself on a grenade and his single body absorbs enough of the blast so spare those in close proximity. Those standing in the immediate vicinity of this guy had to have been absolutely shredded. I'm guessing at least one claymore, or equivalent on each side.

[PowderMonkey]

Death toll is sure to climb as the hours pass. A lethal additive to these explosives is a liberal coating of rat poison to the shrapnel. It inhibits the blood's ability to clot. Thus, severely wounded victims slowly bleed out and die.

[reed13k]

Makes sense that would be about 2 platoons or a battalion if they were in drilling formations. I’m guessing a vest with lots of shrapnel would do the trick and be undetected in formation. If they were wearing packs it would be even more unobtrusive and potential larger.

[tanuki]

Thanks for the visual. It is difficult to conceive of how such a horrific casualty count could occur without it.