Wednesday marks 10 years since a mass shooting at Sandy Hook Elementary School in Newtown, Connecticut, killed 26 people, including 20 children.

Isaiah Márquez-Greene was just 8 years old when he survived the shooting. His sister, Ana Grace Márquez-Greene, was one of those killed.

Now an 18-year-old, Isaiah shares a moving note to his younger self about his life loss in the “CBS Mornings” series Note to Self. 

Dear Isaiah, 
You’re eight years old. You are the light in the eyes of your mother, father, and your sister. You weren’t born into a rich family, but you have a rich family history. You are a proud descendant of enslaved people. Your parents teach you so much about your Puerto Rican and Black heritage. You are surrounded by family and friends in Canada, Puerto Rico, and the United States. When I look at you, Isaiah, I see a smart, funny young kid who loves hockey, Star Wars, sharks, Legos, and God. Hold on to the lessons you learn from Him; you will desperately need them. 
You have been living in Winnipeg, Manitoba for three years. Your father got an exciting job there as a music professor. But in the summer of 2012, you will leave Winnipeg and move back home to Connecticut. On a cold, dreary morning just weeks before Christmas, your 6-year-old sister Ana, your best friend, will be killed at Sandy Hook School.  You, Isaiah, will somehow escape the building. But once out, you will all need a lot of help. Your friends from Canada and from SHS will be the first to come. They will come to play with you so you won’t be alone. You will fly to Los Angeles for a Kings hockey game. You will meet Stevie Wonder and he’ll dedicate a song to Ana in the middle of Madison Square Garden. You will also still be required to make your bed. And study hard. You can take comfort in that even on the days your parents won’t want to get up—they will get up for you.  
Isaiah, this terrible thing will happen, but you will be so much more than a Sandy Hook shooting survivor. Your parents will let you be a kid, but insist you be a kid with big dreams. You will still love music and play hockey. You will find your own voice, even speaking alongside Bernice King and earning a spot at one of the most prestigious boarding schools in the country. While there, you’ll become a student leader, in a role earned by only 12 students in the senior class. You will be fluent in Spanish. When you get older, you’re gonna want to practice law to help kids and families like yours. 
The Sandy Hook School shooting will change your life. You will go from a loved big brother with a 24/7 sidekick to an only child in under ten minutes. And I won’t lie, it will leave you lonely and it won’t ever stop hurting. However, you will prevail. Imagining who she would be if she were still here will keep her alive in your heart because you knew her better than anyone else did. That’s what will help you in your toughest moments. 
Remember the time Ana sang along as you played “Come thou Almighty King” on the piano? Remember how she sat next to you on that bench, and you played like you had all the time in the world? 
Isaiah, hold strongly to these memories, as they will soon become some of the only memories you’ll have of your sister. 
As you grow up and deal with your loss, one of the biggest struggles you’ll have is telling others about it. In fact, sometimes you’ll choose to tell new people you’re an only child when they ask. You’ll still think about Ana all the time, but any words you have to say about her will be unable to come out of your mouth. Don’t feel bad about that.   

One day you’ll begin to realize that another way you can keep her alive is through your words about her. The words will come. You will learn that by keeping her alive, you are calling attention to all those who have senselessly lost their lives due to gun violence and the inaction of our nation’s leaders. 
One day you will no longer be eight. You’ll have a life to sort out. You will have to decide what kind of person you will want to be despite the pain you carry. You will also have to use wisdom in choosing the company you keep. But throughout your young life, you will have the blessing of good friends. Friends who will be with you in the tough times. 
As an 18-year-old, you still won’t know where life is gonna take you. But you should always remember you have a community: Your friends, your family, your God, and your sister, still sitting next to you on the piano bench. 
One day you will sit where I am – waiting to hear from colleges. You will be a Sandy Hook survivor – but you will also be a regular kid. You will be more than ready to start your adult life and meet new friends. You will tell them, when it’s right, about the sister who sang when you played the piano.