Why does this code cause a segmentation fault in Node.js v0.10.31 on a Mac?

var foo, bar;
foo = new Uint8Array(20000);
bar = new Uint8Array(20000);
for (i = 0, j = 0; i < foo.length; i += 2, j += 2) {
    bar[i + 0] = foo[j + 0];
    bar[i + 1] = foo[j + 1];
    bar[i + 1] = foo[j + 1];
}

I realise that this routine makes no sense, especially the duplicated line, but this is a vastly reduced version of a real routine that has an actual purpose and appears to cause the same issue.

What I'm looking for is an explanation, if possible, on why it consistently crashes node.js.

For the record, it fails when i and j hit 11780.