I was walking to class on Monday, reading through emails and speed-walking to make sure that I wouldn’t be late, when one particular email caught my eye. It was from a friend. The subject line read, “your brother,” and the only word I saw in the next line was “bombs.”

My little brother spent the past year training for the Boston Marathon. I thought Patriots’ Day was a national holiday until I stopped living in Boston; there, it is a statewide holiday. I live near Heartbreak Hill, so my brother and I would walk over to the grassy areas of the road and cheer on the Kenyan runners as they flew by wearing their flags every year. We chased each other along the sidewalk, cheering until we lost our voices. This year, he was part of the race.

And I was so proud of him.

But yesterday, the marathon wasn’t a display of human achievement and beautiful movement. For me, it was that chilling, heart-shattering moment of looking through the headlines, desperate for information from anything I could find.

I had no idea what to do, so I called one of my friends on the cross-country team and gave him my brother’s running stats and times, hoping he could tell me that Nico was OK. I was clinging to everything. And all I could think about was: Why didn’t I call him to wish him good luck? What was the last thing I said to him?

Marathon Monday was terrifying for many members of my family and my friends back at home. But in the background of explosions and confusion and the crowds of frantic, scared people away from their homes, I saw so many signs of heroism.

My mother got into the city, despite the locked-down streets and blockages. With a friend of hers, she managed to get through the crowds and passed policemen blocking the streets to find my brother, who had to borrow eight different people’s cellphones to text her and tell her where he was. She was a lioness that day. The kind of mom who lives up to the superhero status she had in my eyes.

My friends from across the city posted messages about having open couches and corners and beds for anyone who was lost in Boston and needed somewhere to stay.

Headlines about runners who left the finish line and went directly to the hospital to donate blood for the people injured in the explosions appeared and were all over Twitter.

We may be known as “Massholes,” but I saw love pouring from every corner of Massachusetts towards all those in need. I have never loved Boston as much as I did yesterday.

Someone told me once that we can remember what is beautiful in the world if we remember to look for the random acts of kindness that take place in the face of tragedy.

I read the news while waiting for more information about my mother and my brother and felt a little better because I believed that someone out there would help them if they could. Just as I knew Nico would, too, if someone needed him while he was out there running.

I have never been so relieved to hear his voice as I was when he called me yesterday evening. A little out of breath, tired and in a lot of pain (he finished the marathon), we joked about how hard it would be for him to climb the stairs the next day. I told him that I loved him, and remembered how lucky I was to say that to him whenever I wanted.

Yesterday helped me remember the communities I never really thought about having, from my friends who immediately texted and emailed and left class to call me, to my fearless mother, to my friends back in Boston and around the world. I think too often I wander through my work and daily routine without appreciating all that I have been given.

Yesterday I was given the gift to say “I love you” again to my beloved little brother. I will never forget this gift.

Diana Enriquez is a senior in Saybrook College. Contact her at diana.enriquez@yale.edu .