Express - res.send() works once

I'm new to Node and Express, I was trying to make something with Express just to get started, then I faced this problem.

First res.send() works well, but the second one doesn't fire.

Here's my code:

var express = require('express'),
    app     = express(),
    fs      = require('fs'),
    visits;


app.listen(8080);

app.get('/', function(req,res) {

    res.send('Hello');

    fs.readFile('counter.txt','utf-8', function(e,d) {

        if (e) { 
            console.log(e);
        }
        else {
            console.log(parseInt(d) + 1);
            fs.writeFile('counter.txt',parseInt(d) + 1);
            res.send('<p id="c">' + ( parseInt(d) + 1 ) + '</p>');
        }

    })
...

'Hello' is sent, but res.send('<p> .. </p>'); isn't. If I comment res.send('Hello');, visitors will be shown.

Thanks in advance.