Removing Submenu from Menu

Question

Thesis appears to automatically add the sub-menus (sub-menu ul) to menu parents if childs exists. I have a specific need to remove this html from a particular menu.

The menu name is: second_level

Not sure if there a hook to do this.

I'm trying to remove these from the menu name above.

<ul class="sub-menu">...</ul>

I'm not trying to remove the class but the UL's.