reading xml node attribute returns null

I am attempting to get the value of attribute "city" from the node "yweather:location" but it is returning a null value.

This is what I have attempted:

public class Location
{
    private String town;

    public String Town
    {
        get { return town; }
    }

    public void updateLocation(String woeid)
    {

        String query = String.Format("http://ift.tt/1CCuImR}", woeid);

        XmlDocument weatherData = new XmlDocument();
        weatherData.Load(query);

        XmlNode channel = weatherData.SelectSingleNode("rss").SelectSingleNode("channel");
        XmlNamespaceManager man = new XmlNamespaceManager(weatherData.NameTable);
        man.AddNamespace("yweather", "http://ift.tt/NpgW1h");

        town = channel.SelectSingleNode("yweather:location", man).Attributes["city"].Value;

    }

}

Why is this returning null?