He said it was TNT (which you can spawn with Level.spawnMob and change render type to falling block). I found that dropped item entities are better for this, though.
true. dropped Item is way more easier to spawn/setblock.
and with entityaddedhook, it works perfectly. but the problem is that it will be picked by player. well, I could make the distance a bit far so it cant be picked, but in multiplayer, it will be messy cuz other player can actually pick that.
+item will be killed by lava/fire