alive. >> reporter: nurses, relentless in their pursuit to save lives. >> my fear is we're going to have to do this again. i mean, every time there's a surge and i'm putting on my scrubs in the morning, i'm always kind of in disbelief. >> reporter: while fighting an in visible battle. >> i do feel like it is like a war. >> reporter: a war they vow to keep fighting. >> i don't think people fully grasp how important that issue is and will be in the weeks and months ahead. great reporting. shifting gears to the super bowl, you don't need to be a football fan to enjoy super bowl commercials. up next, we have a sneak peek at some of the celebrity cameos coming up in the big game tonight. works on that too, and laststs 12 hours. 12 hours?! who studies that long? mucinex dm relieves wet and dry coughs. trelegy for copd. [coughing] ♪ birds flyin' high, you know how i feel. ♪