int y = pos.blockY;
int z = pos.blockZ;
Block block = entity.worldObj.getBlock(x, y, z);
Block blockBelow = entity.worldObj.getBlock(x, y - 1, z);
if(blockBelow.isAir(entity.worldObj, x, y - 1, z) && block.getBlockHardness(entity.worldObj, x, y, z) != -1 && entity.worldObj.getTileEntity(x, y, z) == null) {
EntityFallingBlock falling = new EntityFallingBlock(entity.worldObj, x + 0.5, y + 0.5, z + 0.5, block, entity.worldObj.getBlockMetadata(x, y, z));
if(!entity.worldObj.isRemote)
entity.worldObj.spawnEntityInWorld(falling);
}
}
break;