List<Queue> gets null while it should not be?

 public class MyClass
    {
        private List listOfItems;
        private int someInteger;

        public MyClass()
        {
            List listOfItems = new List();
            listOfItems.Add(new Queue()); // THIS WORKS
            someInteger = 0; // THIS WORKS
        }

        public void SetValue()
        {
            someInteger = 1; // THIS WORKS
            listOfItems.Add(new Queue()); // THIS FAILS, WHY?!?
        }

    }

MyClass test = new MyClass();
test.SetValue();