Transcript for 'This Week' Game Changer: ALS Ice Bucket Challenge
And now the unforgettable story of Pete Frates. You may not know his name but you know what he inspired. That viral video craze that had America shrieking and shivering and giving like never before. The ice bucket challenge may have helped for a cure of a paralyzing disease. John donvan looks back at how it all began and what it really means. Reporter: Remember this? Yes, of course you do. There was a time this year when new videos like this were hitting the internet every few seconds. If you weren't in one of these yourself, then you saw a whole lot of them. You saw news teams doing it. And athletes. And showbiz types. And one guy who was a president once. If you wondered how this caught on so big and so fast, then you need to know about this guy. Frates is swinging the bat with an awful lot of confidence. Reporter: Pete Frates whose own thing was baseball, a game he played phenomenally well, as he did a lot of other sports. Let his mom and dad tell you that. He was all of two years old when we put him on skates. The second he hit the ice he never stopped and eventually became captain of his high school hockey team. He was a great football player, a better hockey player, but baseball, he was playing it like a contact sport. Reporter: In terms of contact, between bat and ball, Pete had long stretches of batting 400. That's a grand slam home run for peter Frates! Reporter: Now we get to some irony about all of that. All of this bucket stuff was meant to raise funds for research into the disease known as als, also known as Lou Gehrig's disease named for the great Yankee ball player who died of it. So Pete played ball and then the irony, Pete got als also. That's why now the wheelchair and the other apparatus, it's to compensate for the rapid loss of the use of his limbs since 2012, something that frankly, his mom was sure medicine must have found on answer for since Lou Gehrig. I figured in 75 years something happened. We've put people on the moon. We've done all these things. I assumed some progress has been made. Okay, what's the treatment. There's no treatment. Reporter: That's what happens with rare diseases which als is, not enough people get it to track significant research funding. That's the part that Pete decided to try to change. He was ready, sat, told us the vision, and said what an opportunity we've been given to change the world. He said -- these are his words six hours after diagnosis. He said I'm going to get this disease in front of philanthropists like bill Gates. Reporter: He and a friend from New York who also has als had seen occasional fundraising efforts who were throwing ice water at other things for good causes. After passing ideas back and forth, Pete staged this massive bucket challenge in downtown Boston. Three, two, one, dump them! Reporter: And that, so many people at once, so many buckets, is the one that caught a wave in Boston and its key idea, make a donation in 24 hours or take the ice water. Well, the chain reaction started. Pardon the pun but it was like a waterfall. It was amazing, stupendous, incredible. That was week one. Then when it went national I'm saying, my god, this is what it feels like to be in the middle of a viral ice storm. Reporter: So that's how it all began. What about the impact? Here's a man who is unable to move his arms and yet his reach has become huge. He wanted bill Gates to be involved. Well, look at this. He wanted word out about als. Well, look again. Now, there were some criticisms not unreasonable, that giving people the option not to donate and do this instead was giving them an excuse not to give and that people in the videos were making this more about themselves than the cause. But at the als foundation, they have no problem with what Pete fray teas has helped them set off. The awareness level of als just went through the charts, went off the roof. It actually gave the name als, it gave it a credibility that was different than it previously had. Prior to the ice bucket challenge, most people, if you said als, they would not have been able to tell you anything about it. Reporter: One other impact is how this made Pete and his own family feel. There's a reason that he's not appearing in this story talking himself. I cannot thank all who have participated thus far enough. Reporter: This man who spread the story so far and wide can no longer speak. We are hoping to keep the momentum going. I'm doing this in honor of Pete Frates. Pete Frates. Reporter: Again to his parents to say what it's meant to them that so many people got on board. The power, the joy, the hope that came through on those videos back to Pete, number one, and ourselves and anybody, oh, we absolutely felt it. It's almost like we got a visual we're with you from every person do it. Thank you, gratitude. It doesn't go to the soul as much as I want it to to tell people what this means to us. When I say us, I don't just mean John, Nancy, I don't just mean the Frates family. I mean the als community. The head doctors in this field have said to us over and over again, this is it. When the treatment is found and the cure is found, it will go back to August 2014 as the tipping point in the trajectory of this disease. And your son. And it was Pete Frates. Reporter: For "This week," John donvan, ABC news, Boston.
This transcript has been automatically generated and may not be 100% accurate.