but zack is firm. >> no ben and josh, come on. >> reporter: they run inside where our producer meets them. >> there's some guy outside. >> he has video games. >> that's really impressive. zack, he immediately right away said, come on, guys. >> reporter: time to go tell zack how proud his mothersome your brothers are lucky to have such a great big brother. they really r >> you are. a great big brother. >> when the guy pulled up, what was it that made you think that this might be a dangerous situation? >> my mom and dad always talked to me about strangers coming up to me and saying help me find my dog or help me with something. >> you're our hero today. you're the hero of the day. >> yes, you are. [ applause ] >> reporter: safety expert patty fitting gerald says zack is an example for all kids, don't be embarrassed to say no to strangers. >> i tell kids be a big mouth kid. it is okay to yell, to scream, to say, whoa, stop!