jQuery Grid Plugin - jqGrid

I'm new to jqGrid.

Our use case needs us to *expand all nodes under root node on click*

I tried setting the expanded property to true for all non-leaf nodes & non root nodes, however doing so makes the level 1 node disappear also the other nodes expand.

Here is the jsFiddle: http://jsfiddle.net/SQzAC/1/  (If you click the root node you will notice that level 1 was hidden) 

I guess I am using the API in a wrong way and instead of setting the expanded property at load time I should set the expanded property for all non-leaf and non-root nodes in loadComplete event.

What is the right way to achive the desired result? TIA