An American activist who was killed by a car bomb in Iraq (search) earlier this month was remembered Saturday for her dedication to humanitarian causes and her personal mission of counting civilian casualties of war.

Many of the more than 600 mourners, including friends, family, colleagues and journalists who traveled from around the world for her funeral, shared memories of Marla Ruzicka's (search) boundless energy that helped her accomplish much in her 28 years.

Kevin Danaher, co-founder of San Francisco-based Global Exchange (search), a nonprofit international human rights organization, said Ruzicka's magic was understanding and showing unconditional love.

"That's why a 28-year-old woman from a small town in Northern California has so many people around the world grieving for her," Danaher said.

Ruzicka traveled to Iraq before the March 2003 U.S.-led invasion and later founded a group called CIVIC, the Campaign for Innocent Victims in Conflict, whose aim was to tally the number of Iraqi civilian deaths in the conflict. She was also instrumental in securing millions of dollars in aid money from the federal government for distribution in Iraq.

On April 16, she became a statistic herself when she was killed in a car bombing in Baghdad, along with her interpreter and another foreigner.

The Rev. Ted Oswald, who conducted the Mass at St. Mary's Catholic Church, said it was sad that it took a tragedy to bring to light all the good Ruzicka did. Oswald said she usually accomplished things in her own quiet way, though there were exceptions.

"There's no doubt in my mind that the good Lord has his hands full right now," he said, referring to Ruzicka's sometimes outspoken nature. "Not only does he have his hands full, but heaven will never be the same."

Oswald also recounted the time when an 8-year-old Ruzicka sold rocks door-to-door to buy carnations for her mother. She even managed to get the flowers on the cheap from the florist.

The upbeat homily brought laughter from the audience, which included actor Sean Penn, who said he counted Ruzicka among his heroes, and U.S. Sen. Barbara Boxer.

Ruzicka's activism began in this town 350 miles north of San Francisco, where she worked at a convalescent home, helped abused children and started a girl's soccer team in high school. Eventually, it led her around the world — to parts of Latin America, Africa and the Middle East, where she often traveled in harm's way.

With passion for her cause and an unbridled capacity for having fun, she was remembered as a force of nature, a cross between Mother Teresa and Buffy the Vampire Slayer, said Quill Lawrence, a radio reporter for the British Broadcasting Corp.

Ruzicka often arrived in war-torn places unprepared and nearly broke, he said. But Lawrence said she quickly managed to win over the hearts of those she was helping and those whose help she needed.

Lawrence said Ruzicka repaid favors with her friendship, kindness and a ready smile. She organized parties, slipped heartfelt notes under the doors of friends' rooms and hugged guards at military checkpoints.

"She made me feel like I was the greatest person on earth," Lawrence told the crowd. "I have it in writing. And I know all of you do as well."

Bobby Muller, chairman of Vietnam Veterans of America Foundation, said the true value of Ruzicka's work was her ability to counter people's cynicism.

"Marla demonstrated the fact that an individual can make a profound difference in this world," Muller said. "This woman was our inspiration."

But Ruzicka was not satisfied with herself, looking in the mirror each day and vowing to do better, said Catherine Philp, a friend and reporter for The Times of London. She didn't know she was already better than most people, Philp said.

Ruzicka's organization, CIVIC, is urging people to honor her memory and her cause on May 3 by holding vigils to bring attention to civilian casualties of war. Another memorial for Ruzicka is planned in Washington on May 14.