Javascript Unresponsive Script Error

I am trying to get data to load on my chart from an API. All the data is getting to the chart correctly, but the chart doesn't load and I get the unresponsive script error. I'm using Highcharts. Any suggestions? Thanks. My code is below.

Model

public function ajax_get_chart() {

    $quotes = $this->rest->get('api/1/BTCUSD/trades/fetch');
    $series_data = array();
    $results = $quotes->return;
    $i = 0;

    foreach ($results as $quote)
    {
        $series_tmp = array(
            'date'      =>  $quote->date,
            'price'     =>  $quote->price
        );
        $series_data[]= $series_tmp;
        $i= $i+1;
    }
    die (json_encode($series_data));
    return TRUE;
} 

Javascript

$(document).ready(function() {
    var chart;
    $.ajax({
        url: "/chart/ajax_get_chart", // the URL of the controller action method
        dataType: "json",
        success: function(result) 
        {
            chart = new Highcharts.Chart({
                chart: {
                    renderTo: 'container',
                    defaultSeriesType: 'bar'
                },
                title: {
                    text: 'Stacked bar chart'
                },
                xAxis: {
                    title: {
                        text: 'Price'
                    }
                },
                yAxis: {
                    min: 0,
                    title: {
                        text: 'Date'
                    }
                },
                legend: {
                    backgroundColor: '#FFFFFF',
                    reversed: true
                },
                tooltip: {
                    formatter: function() {
                        return ''+
                            this.series.name +': '+ this.y +'';
                    }
                },
                plotOptions: {},
                series: result
            });
        }
    });
});