Most kids celebrate birthdays with treats, a party, and dressing up in a theme. Brolin Hardin’s 5th birthday party had all of that; complete with balloons and a superhero theme.

But one key component to the celebration was missing: Brolin himself.

“When you experience something like this you feel very alone because you don’t think that anyone can quite grasp the pain that you feel. But little tokens like that, little acts of service where people will remember your son, it means the world to me,” his father John Hardin said.

Brolin died after falling into a pool during a family vacation to Dallas in October 2015. His drowning left his family in shock, but his parents found a silver lining in their grief. Brolin’s organs, donated after his death, were able to save the lives of four people. His kidneys went to two men in their fifties, his liver went to a young boy, and his heart is now beating in the chest of a toddler in Florida.

“My ideal for that situation would be to watch them grow from afar. I don’t want to feel like I have to be a part of their lives but I’d like to see the little pieces of him in the world,” Brolin’s mother Becky Hardin said.

The Hardins have received thousand of messages of support over the last six months.

“The love that we receive from others is really healing for us. We are overwhelmed by the fact that they would still think of us, as their lives have gone on and do such special things for us,” Becky said. “It’s amazing that they still remember our little Brolin and his story and they share with us often how he has impacted them, and how our family has given them hope and strength, in whatever way we’ve done that.”

The party on Monday, hosted at Kid Central, where Brolin went to daycare, was full of laughter and tears. After a short prayer from Brolin’s dad, the group happily sang ‘Happy Birthday’ and tearfully released balloons into the sky.

“I miss him a lot today, especially. Every day. But, today especially,” Becky said. “We should be having a kid licking the icing off a cupcake, and jumping off of whatever, and spitting on the candles, and him singing happy birthday to himself louder than anybody else.”

John honored his son in his own special way, donning a Batman and Superman t-shirt, organ donation pin, and the cap from Brolin’s Tee-Ball team, the Blue Rocks.

John also has a new edition to his SUV, a license plate reading “Live Bro.”

“Obviously short for ‘Live Brolin.’ It’s in blue which was his favorite color. And it’s a reminder to me at least to ‘Live Brolin’ because of all of the people in our family that need to ‘Live Brolin’ which kind of going back to what ‘Live Brolin’ means it just means to be a little bit silly and not take yourself so seriously. Of all the people that need to remember that, it’s me,” he said.

“Every day was an adventure to him. Every day he had a smile. And that’s what you really miss is just that look of pure joy and innocence and purity that came with Brolin,” John added.

“I miss his laughter, that sparkle in his eyes, the mischievous grin, telling him not to do dangerous things all the time, just– I just miss the feeling of him in our home. The hugs. He was the best hugger. Telling him to go to bed a thousand times in the night because he  has to come out and tell me that he loves me,” Becky said.

Brolin’s school, Wester Elementary, has planted a tree in his honor, which is scheduled to be dedicated on Friday.

Brolin’s parents have taken each day one day at a time. They said they have slowly begun to learn how to cope.

“Find the good in every day. Try to make this life as joyful as I can. Try to have, when possible, more happy moments in a day than sad moments,” Becky said.