Transcript for A New York firefighter honors shooting victims by performing acts of kindness
week filled with such heartache, a story about someone taking action for good. His amazing joir -- journey, and how it's spreading across the country. Reporter: A man and a van. And a mission. That's Tommy Marr's story. He sees something bad in the world and pushes back with kindness. It started after the October mass shooting in Las Vegas. The plan was, I had bracelets made with each person that died, and I would show up in their town, and do a random act of kindness in their honor. Reporter: He's in that van, getting to all the communities from West Virginia to California. In each place, performing an act of kindness. In Pennsylvania, in a laundromat, he taped envelopes quarters in honor of bill wolf. In California, hand warmers for construction workers. In California, gift cards passed out by his daughter in honor of Kerri Barnett. As his daughter says of her dad -- He's always been the guy to just put himself before someone else. He'll do anything for anyone. Reporter: And it's catching on. Instagram is filling up with pictures of checks picked up by strangers with the hashtag #honor51. As he himself says -- For me, there's no better way to honor people. Reporter: John donvan, ABC news. And he tells us he's heading to Florida now to honor those lives lost in the school shooting. Keep an eye out for his kind acts. Thanks so much for watching. Have a great evening. Good night. Ribeiro: Here's a sneak peek at tonight's "Afv." We know you're gonna love it.
This transcript has been automatically generated and may not be 100% accurate.