DANVILLE — It was a beautiful, but unusually hot Danville evening on Oct. 26, 2003, when Bob Pack got the call all parents dread.

His 10-year-old son Troy and 7-year-old daughter Alana had gone out for Slurpees with their mother Carmen and best friends Hunter and McKenna, when a gold Mercedes jumped the sidewalk. They were run down by the drunk woman, who was heavily medicated with prescription medicine.

Within hours, Troy and Alana were dead. The driver, Jimena Barreto, was on the run.

Now, a decade later, Barreto is behind bars at Valley State Prison in Chowchilla, likely never to be released. And the Packs are busy themselves with their daughter Noelle — now the same age as Alana was when she died — and though they've come to accept the circumstances, the grief creeps in when seeing Troy and Alana's childhood friends, all grown up and moving on to college.

From left, Bob and Carmen Pack, of Danville, talk to Kiat Favro during their daughter's soccer practice in Danville on Oct. 8, 2013. (Doug Duran/Staff)

"It's hard to accept it's been 10 years without our kids," Pack said. "It makes us wonder what Troy and Alana would be like … It's an emotional toll, but we deal with it."

A former America Online executive and vice president of NetZero, the soft-spoken Pack has turned his family's tragedy into a mission to help others. He has used his background to design an electronic update to the state's Controlled Substance Utilization Review and Evaluation System (CURES) database, enabling doctors to see what prescriptions their patients already have, and giving the Justice Department immediate alerts of possible abuse.

It took seven years and multiple attempts, and it faced opposition from some of the state's most powerful lobbyists, but Pack and the bill's author, Sen. Mark DeSaulnier, D-Concord, finally succeeded in getting SB 809 passed and signed by Gov. Jerry Brown on Sept. 27. It's a key preventive step, Pack said, to ending "doctor shopping."

DeSaulnier said Pack's story was the genesis for the law, which will provide money to upgrade and sustain CURES within two years, using small license fees paid by doctors and pharmacists.

"He's been absolutely tenacious, and a great partner to work with," DeSaulnier said. "It's an example of one person taking his personal tragedy and making the effort so other people don't have to go through it."

After locating Barreto, investigators discovered she'd been downing vodka and had taken more than a dozen painkillers before the accident. She'd visited multiple doctors in the same Walnut Creek Hospital to get multiple prescriptions for Vicodin and Flexeril, a muscle relaxant.

Outraged by how freely doctors had prescribed the narcotics, Pack founded the Troy and Alana Pack Foundation to work with politicians, police and advocacy groups for tougher public safety legislation, began anti-drunk driving efforts in schools, and fought district attorneys to change the charges against Barreto from vehicular manslaughter to second-degree murder.

Jim Doliber, whose children Hunter and McKenna survived the accident, said he's constantly amazed by Pack's patience, selflessness and resolve.

"I would get angry, but Bob would never get angry," Doliber said. "He focused on what he could do … He'd just say, 'Well that door is closed, I'll find another.'"

In 2005, a jury convicted Barreto of murder, and the former nanny was sentenced to 30 years to life.

During the trial, Carmen was pregnant with twin boys, that she lost in two weeks after the trial. When she recovered, the Packs tried in vitro fertilization again, and daughter Noelle was born.

Bill Barnett, Pack's longtime friend and former roommate at USC, said seeing what Pack has gone gives him strength.

Noelle Pack, 7, of Danville, stretches with other members of her soccer team during practice in Danville on Oct. 8, 2013. (Doug Duran/Staff)

"When I get down, I think about Bob," Barnett said. "It's amazing how he's persevered through the ups and downs … I don't know if many people would've gotten through this."

Pack isn't finished with his Sacramento crusade. He's starting a petition drive for the Troy and Alana Pack Safety Act, which would make consulting CURES mandatory for all doctors before prescribing narcotics — a provision dropped from the bill — and raise the state's $250,000 cap on damages victims can win from malpractice suits.

Jamie Court, president of Consumer Watchdog, an advocacy group that lobbies for health insurance reform and helped draft the initiative, called Pack's willingness to repeatedly take on the powerful medical establishment "remarkable."

"It's more than David versus Goliath; it's Bob Pack versus five different Goliaths," Court said. "I've never seen either a whistle-blower or survivor of a medical tragedy who's had the same kind of authentic power as Bob Pack has."

Besides his advocacy, Pack's life revolves around Noelle, who turned 7 in May and who shares Alana's love of athletics. Mom Carmen teaches Spanish at an immersion school, and though she says she'll never fully recuperate from the loss of Troy and Alana, between her work, faith, and Noelle, she finally has reason for optimism.

"I feel like life right now is exactly where I left it 10 years ago," Carmen said. "I find myself looking more forward than looking back … I have peace in my heart. I can dream again."

Despite the trials, Bob Pack says the last decade gave him a new outlook.

"It gives me so much satisfaction and helps me heal, knowing (my work) might help someone else," he says. "I wish it hadn't taken a tragedy to see that."

Contact Jeremy Thomas at 925-847-2184. Follow him at Twitter.com/jet_bang.