College Kids Trapped in Sewer

by Katya
(Doha, Qatar)

Hi, I need help remembering the name of a movie about some college kids trapped in a sewer.

A girl thinks the only way she can get this boy to be interested in her is to spend a few days with him. So she takes him and his friends down a man hole and jams the door closed.

One by one, each person dies until there are only three people left. Then the girl opens the door, but the guy catches her. He now knows she jammed it in the first place.

Any ideas on this one?