Best watch order for The Descent!

Title: The Descent
Original Title: The Descent
Scream your last breath.
Release Date: 2005-07-08
Director:
Chronology:
Production Company: Celador Films
Runtime: 99 minutes
Links: Website - IMdb

Title: The Descent: Part 2
Original Title: The Descent: Part 2
Fear runs deeper
Release Date: 2009-10-14
Director:
Chronology:
Production Company: Celador Films
Runtime: 94 minutes
Links: Website - IMdb