U.S. Army Spc. David Gustafson hugs his fourth-grade cousin, Thomas Marrs, who turned 10 years old on Friday, during a surprise visit at Harbor View Elementary School. Gustafson, who is stationed with the 10th Mountain Division out of Fort Drum, N.Y., and has been deployed to Afghanistan, came and wanted to surprise his little cousin. (SCOTT SMELTZER, Daily Pilot / December 21, 2012)

His time at Harbor View Elementary School's morning flag deck ceremony made him as nervous as just about anything the Army's thrown at him so far.

But for Spc. David Gustafson — who served in Afghanistan, Germany and now Fort Drum in upstate New York — it was all in good cheer and in the family. After all, the infantryman was at the Corona del Mar campus as a holiday/birthday surprise for Thomas Marrs, his cousin who turned 10 Friday.

After Principal Todd Schmidt announced it was Thomas' birthday, he alluded to Gustafson's service. Then Gustafson came out onto the blacktop dressed in his Army fatigues, boots and all. To claps and cheers, the cousins hugged and exchanged a few words as media and parents' cameras rolled and clicked.

"I was about in just as much shock as he was when I went up there," Gustafson said afterward. "He looked a little surprised, and I was as well."

"I'm not gonna lie," he added. "I was a little bit nervous. It was a little more nerve-wracking than I thought it would be."

Gustafson, 24, has been in the Army about three years. He's with the 10th Mountain Division.

Thomas was excited but shy with all the attention.

The fourth-grader looks up to his cousin, said Tony Marrs, Thomas' father.

"That's his idol right here," Marrs said. "He wants to be in the Army because of it … it's his mentor right here. It's his cousin. These guys grew up together."

The two of them have always liked fishing together, Marrs said, and when Gustafson went jogging, Thomas rode his bike alongside him.

"Every time he comes from his deployment, he always comes and sees Tommy," Marrs added. "They're really good friends."

Amid the media and campus community, it was certainly a family event that morning. Gustafson's father, Robert Gustafson, visited from Eugene, Ore. Thomas' grandparents, Steve and Linda Warwa, attended as well.

"I'm very proud. My son's a hero every day," said Robert Gustafson, who attended sixth grade at Harbor View. "It chokes me up, the fact that this is the greatest … I'm just blessed. We have a really, really tight-knit family."

Linda Warwa is no stranger to Harbor View, having taught there for more than 45 years. She's still around campus as a substitute.

"We tried to end [the week] on a happy note," she said, in reference to nationwide talks of campus safety after the shootings in Connecticut. "I think everybody wins. Everybody wins on this kind of thing."

Thomas and his classmates have been sending Gustafson's platoon letters for a while now.

David Gustafson said they mean a lot to the soldiers, even though they don't personally know the young letter-writers.

"There were some good letters, some cute kids," he said. "They brought us some laughs and they had interesting questions … it's nice to get a letter from somebody you don't know who shows their support."

After flag deck, Thomas and his classmates went back to their classroom for a "cereal party" stocked with everything from Cap'n Crunch to Special K. Once in teacher Kristin Botta's fourth-grade classroom, Gustafson fielded some questions from Thomas' classmates.

"Is the Army cool?" (Definitely yes.) "Do you drive a tank?" (No.) "Did you fight the Nazis?" (Definitely no.) "Where do you sleep?" (Usually on a bed.)

Thomas, short on words but happy nonetheless, told the Daily Pilot he was having a great 10th birthday. He felt "good" having his big cousin here to share his day with him.

"Thomas is just a sweet kid," Botta said. "He's so thoughtful and kind. I'm just so excited for him and it's wonderful that he has special experience, especially today, to kick off winter break."

bradley.zint@latimes.com

Twitter: @bradleyzint