May 16 was unlike any other in Hadzic's life so far.
"I was just shaking before my speech because I knew what I was going to say. I didn't know how I was going to say it. And it really was a rough, rough day," Hadzic recalled.
Earlier that day, Hadzic had attended the funeral for his late father, Miralem Hadzic, who died on May 15 after a monthslong battle with pancreatic cancer.
VIDEO | Watch Alem Hadzic's full speech
High school valedictorian delivers moving speech following father's funeral
The Early College High School graduate said he helped bury his dad and then drove with his younger sister to his graduation.
"I think people could tell there was something off because I was very silent," Hadzic said. "People were trying to talk to me, and I would just kind of blow them off."
Although it would have been understandable if Hadzic didn't attend graduation, held at the Dallas College Brookhaven Campus, or asked not to make a speech, he decided to go ahead with it and his speech ended up bringing tears and a standing ovation from the audience of students, families, teachers and administrators.
"When I went off script, I was just speaking from the heart. My brain was off," Hadzic recalled. "I was really close to breaking down but when I looked in the audience and ... I saw people who were touched by what I was saying, I saw people who felt the same things I was feeling and suddenly, I didn't feel so alone in that moment. That's when I knew I could get through it."
Hadzic revealed in his speech that his beloved dad had been diagnosed with cancer in January, a fact he had kept from many, and that he had died but that he wanted to share his dad's story more widely in order to inspire his peers to know their why.
"I said that I didn't want to be up there but I couldn't throw something away that he worked so hard for me to achieve. And that's why I'm going to college, and I'm going to work every single hour of every single day, and I'm going to do it for him," Hadzic recounted.
"I wanted to encourage everyone to do what I was doing, even if they didn't lose anyone. Just do it, like succeed for your loved ones. Those are the people who want you to succeed the most," the high school graduate added.
Hadzic said he and his late dad, whom he described as a "self-sacrificing guy," shared a "very, very close" relationship. They would often do things together, and in particular, they loved to watch their favorite basketball team, the Dallas Mavericks, play.
"Me and him used to always watch basketball together when I was a kid. It's one of my favorite things to do with him. And it's one of the last things I did with him, actually, before he died," Hadzic said.
Hadzic said even though he didn't talk about his dad's health and condition in his last semester, he's grateful now to be able to speak about him while his grief journey is just beginning.
"I'm very glad to be able to spread his legacy. He would have been so proud of me. I already know it. That's what people are telling me," Hadzic said. "It feels good doing what I know he would have wanted me to do."
Hadzic graduated with a 4.0 GPA, earning both a high school diploma and an associate of science degree from Early College. He said he is excited to start at the University of Texas at Austin in the fall and plans to major in chemical engineering.
In a statement, Carrollton-Farmers Branch Independent School District, the school district which includes Early College High School, expressed pride in Hadzic's achievements and his moving graduation speech.
"We are so proud of Alem, and the bravery and vulnerability he showed during the graduation ceremony was truly inspiring," Wendy Eldredge, the superintendent of Carrollton-Farmers Branch Independent School District, said in the statement. "It was an honor to celebrate him, and I'm confident he will do great things in the future."