Dynamic child nodes in xml to columns in sql

I have a programming situation, where i need to select the dynamic child nodes in the xml into Individual columns in SQL server query.

For Ex,.

<persons>
    <ID>1</ID>
    <person>
        <firstName>Jon</firstName>
        <lastName>Johnson</lastName>
    </person>
    <person>
        <firstName>Kathy</firstName>
        <lastName>Carter</lastName>
    </person>
    <person>
        <firstName>Bob</firstName>
        <lastName>Burns</lastName>
    </person>
</persons>

The select should return,

ID FirstName LastName FirstName LastName FirstName LastName
1  Jon       Johnson  Kathy     Carter   Bob       Burns

This child node Person can vary from 0 to n.