return Json error from ASP.NET MVC

I'm trying to return an error message via Json from ASP.NET MVC controller. I want to display carriage returns on the screen, so the error will look like:

Error 1.
Error 2.

instead of "Error1.\u003cbr/\u003eErro2.\u003cbr.\u003e"

Here's my ASP.NET MVC code

Response.StatusCode = (int)HttpStatusCode.BadRequest;
string str = "Error 1.<br/>Error 2.<br.>";
return Json(str);

JavaScript (redacted):

.ajax({...
     error: function(xhr, textStatus, exceptionThrown) {
        $('#result').html(xhr.responseText);
     },

Debugging the xhr.responseText yields: ""Error1.\u003cbr/\u003eErro2.\u003cbr.\u003e""

Any ideas?