How was suspense created in the film I watched in class?

The film I watched was 'What lies beneath.' Suspense was created really well which always built up to something that really gets the audience frightened.

In this scene it creates suspense because as Claire leaves the house we do not know whether Norman did too. AS she drives a shoes falls off the truck. This leaves the audience wondering wether he is at the back or not, and this is a key element of suspense.