Forgot movie title, please help?

It's some movie where theres these people in a like abandoned factory or something. There are lke these teenager type kids and most of them die like one died from like a bag over her head and one gets like stabbed by some other freaky *** dude in the factory. I can't remember the name. Theres like a place in the factory where theres like thi guy sitting in a chair with all these tubes attached to him in like this gl box. All the kids walk in it, I think he kills one of them. i'm not sure i just NEED to remember the name.