private boolean checkSquare(int check_index) {
        HashMap<Integer, ServerThread> players_threads = Server.getPlayersThreads();

        Element element = Server.board.getElement(check_index);
        if (element != null && element.isActive()) {
            if (!element.isBreakable()) {
                return false;
            }
            if (element instanceof Bomb) {
                element.burn();
            } else {
                this.burning_list.add(element);
                this.fire.add(check_index);
                return false;
            }
        }
        this.fire.add(check_index);

        for (ServerThread thread : players_threads.values()) {
            if (thread.getBoardIndex() == check_index) {
                Server.killPlayer(thread.getClientId());
            }
        }
        return true;
    }