can't see obj file

Hi I imported an OBJ file into Unity. When I click on it in the project tab, I can see the wireframe of the mesh in the inspector (although the orientation does not seem right). But when I drag it into the scene, I can't see anything. As you can see from the screenshot, transform is ok; I zoomed in and out, changed the scale. It has mesh renderer and mesh. What can be the cause of this? thanks ![alt text][1] [1]: /storage/temp/76338-screenshot-8.png