If you are going to be killed anyhow, why would you try and fight back to save yourself?

In a situation be it a campus, work place, resort, etc. someone had a weapon such as a rifle or pistol and starts shooting people he/she comes upon. If the route of escape is blocked and eventually he/she will get to your location and when he/she does, you will most likely be shot, why not try and use the element of surprise and attack the gunman? You may succeed saving yourself and others, especially if this life is all you have; I would think you’d fight for it tooth and nail.