all seems fine until the lights start to sway. >> that's when i got nervous. i thought, one of these things is going to snap. >> seconds later, the entire facility collapses. about 70 people struggle to escape, including mack, a reporter for the ft. worth star telegram. >> it's so fast and so chaotic, your first thought is, just get me to safety, wherever this is. >> a tv cameraman keeps rolling as people try to figure out what just happened and if anyone is injured. >> irving fire department. >> the dallas cowboys practice facility collapsed. it collapsed during a practice. >> what has collapsed? >> their indoor practice