This is the story of Life Is Good founder Bert Jacons, as told to Inc. editor-at-large Leigh Buchanan. 

On marathon day, we had 10 people walking around near the finish line, representing the brand. Another dozen were hanging out and cheering people on. I'd been at the Red Sox game and was having a beer with some people afterward when I heard what went down. We got everyone together back at our Newbury Street offices and took count. We were missing one. 

I promised I wouldn't give out the guy's name. He's a good employee who has been with us for a while. He was watching the race and had been standing close to the second bomb. I got over to Mass General. It was chaos. His ex-wife couldn't come because she was taking care of the kids, but I wasn't able to see him or get any information because I wasn't family. I went home not knowing whether he was going to live or die.

The next day, I was able to see him. He was badly burned and wrapped up head to toe. They had been operating on him all night. But in the first 30 seconds, he told me how grateful he was. Because he knew other people were worse.

The day after the attacks, our employees started asking whether we could do something to raise money for the victims and their families. I said no. I felt like we had to get our own house in order, to feel like it was OK to get back to work, before helping somebody else. But we're a brand about the power of optimism. We should be leaders of the spirit when bad things happen. So by Sunday, I changed my position and said we should make a T-shirt.

We looked at what was already out there. A lot of "Be Strong" and "Boston Strong," that tough Irish mentality. I don't knock that. But it's almost like they're suppressing emotion: We're so strong, let's just move on. Life Is Good focuses on what's right in the world.

No matter how you slice it, this was a hate crime. But instantly afterward, all these people--the first responders and the people who helped people on the street and opened up their homes and ran to the hospitals to give blood--performed acts of love. So we created a shirt that says "Boston" on the front and "There is nothing stronger than love" on the back.

Something like that happens, it freezes you. But this got everybody busy. It healed us internally. We have 260 employees, and there is not a single person who did not touch that shirt. From start to finish, we got it out there in just under 30 hours. We're not built to turn something around that fast, but our people figured it out. They worked day and night. We're proud of their hustle.

Our sales died right after the attacks. But after we put the T-shirt on sale, they rebounded pretty quickly. People came to our website for the shirt, and they also bought other things. We got new customers. So the shirt let us be part of the healing. But it helped the business, too.

We sold 75,000 units in the first few weeks--it may be our fastest-selling product ever. All the profits are going to One Fund Boston. We thought we would raise $50,000 or $100,000; we may raise half a million. As for our employee, he is in rehab now, and we're hopeful he'll make a full recovery. He has the right attitude.