Marine Lance Cpl. San Sim, 23, Santa Ana; killed while on patrol in Afghanistan

"When he was in high school, he tried to take his pet rooster for a walk, and a rooster is not really an animal you take for a walk, but that's just what he did," she said.

The only thing he loved more than animals was his family, she said. That love of family eventually led to a military career.

San Sim grew up hearing the story of how his family made it from Southeast Asia to the United States against immeasurable odds.

"My dad would tell him about our family and how the nine of them would run through the jungle for hours each day to escape war in Cambodia, and that really stuck with him," Serene Sim, 25, said.

In the late 1970s, the Sims fled Cambodia, then under the genocidal rule of the Khmer Rouge, for refugee camps in Thailand. In 1985, the family made it to the Philippines, where Sim was born, the last of the family's 11 children.

"To be able to survive that migration is a miracle, and he really understood the sacrifice and the struggle the family went through to get here to have some freedom," Serene Sim said.

It was this family history that gave Sim his appreciation for freedom and life, whether animal or human, she said. "He wanted to be a part of America and contribute and give back to the country that gave us all so much," she said.

But it wasn't until after the Sept. 11 attacks, when Sim was a student at Santa Ana’s Valley High School, that he decided how he wanted to give back to the country.

"He just knew it's what he wanted to do -- we all did, him, my brother and I," said Rossy Morales, Sim's childhood neighbor. "We always talked about it, and how we were going to go fight for our country."

After graduation, he attended Orange Coast College for two semesters and then joined the Marines in 2004.

Morales, 22, said her brother, Jay, enlisted in the Marines on the same day as Sim and fought alongside him in Iraq. She later joined the Army herself and will head to Iraq in December.

Sim's decision to go to war left his family conflicted.

The family had hoped to leave war behind, Serene Sim said, and the Sims are pacifists as a part of their Buddhist faith.

"It was a calling for him regardless and we can't stop him from his journey," said Seng Sim, one of Sim's older brothers.

"The war changed him in a lot of good ways. After the first tour when he came back, he was always saying he loved you. That's not something we grew up a lot with, showing that kind of emotion, but that's something he brought with him and into our family."

Between tours, Sim fell in love with and married Karla Cardenas, a friend of his sister Sarom Sim.

She spoke Spanish and very little English, while he spoke almost no Spanish when the couple met, but they knew they were in love, Seng Sim said. The couple had a son, San Donovan Sim.

Family members said that, just as he was motivated by a sense of duty to family and country when he joined the Marines, Sim was moved by his love for his wife and son to sign up again.