How could I improve this code?

I run a small Skyblock server, and my server tends to hang or freeze for a bit whenever someone restarts their Skyblock island. It acts like a big worldedit just took place.
This is the code that deletes their island, does anyone have any ideas on what I can add or modify to this code to make it perform better?

Code:

  public void deleteIsland(String playerName, World world) {
    if (hasIsland(playerName)) {
      Island island = getPlayerIsland(playerName);
      for (int x = island.x - 50; x < island.x + 50; x++) {
        for (int y = 200 - 200; y < world.getMaxHeight(); y++)
          for (int z = island.z - 50; z < island.z + 50; z++) {
            Block block = world.getBlockAt(x, y, z);
            if (block.getTypeId() != 0)
              block.setTypeId(0);
          }
      }
      this.playerIslands.remove(playerName);
    }
  }

 

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