XML simple access question

programming flash
1 

public class XmlExample extends Sprite {        
        public function XmlExample() {
            var emp:XML =
                <employees>
                    <employee ssn="123-123-1234">
                        <name first="John" last="Doe"/>
                        <address>
                            <street>11 Main St.</street>
                            <city>San Francisco</city>
                            <state>CA</state>
                            <zip>98765</zip>
                        </address>
                    </employee>
                    <employee ssn="789-789-7890">
                        <name first="Mary" last="Roe"/>
                        <address>
                            <street>99 Broad St.</street>
                            <city>Newton</city>
                            <state>MA</state>
                            <zip>01234</zip>
                        </address>
                    </employee>
                </employees>;

I saw this example on flex documentation. To access the element, I could do:

emp.employee[0].address.zip

But I don’t understand why not

emp.employees.employee[0].address.zip

Why they design to skip the top element “employees”? From my understanding, if it’s a arraycollection, then I have to add an extra “employees”.